75 files changed, 189 insertions, 169 deletions
diff --git a/api/src/main/java/io/opencensus/trace/Tracing.java b/api/src/main/java/io/opencensus/trace/Tracing.java
index 316368a5..2f6c891e 100644
--- a/api/src/main/java/io/opencensus/trace/Tracing.java
+++ b/api/src/main/java/io/opencensus/trace/Tracing.java
@@ -91,7 +91,7 @@ public final class Tracing {
     try {
       // Call Class.forName with literal string name of the class to help shading tools.
       return Provider.createInstance(
-          Class.forName("io.opencensus.impl.trace.TraceComponentImplLite", true, classLoader),
+          Class.forName("io.opencensus.impllite.trace.TraceComponentImplLite", true, classLoader),
           TraceComponent.class);
     } catch (ClassNotFoundException e) {
       logger.log(
diff --git a/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsNonSampledSpanBenchmark.java b/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsNonSampledSpanBenchmark.java
index b7b4c533..4b1411a7 100644
--- a/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsNonSampledSpanBenchmark.java
+++ b/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsNonSampledSpanBenchmark.java
@@ -13,7 +13,7 @@
 
 package io.opencensus.trace;
 
-import io.opencensus.impl.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl;
 import io.opencensus.trace.samplers.Samplers;
 import java.util.HashMap;
 import java.util.concurrent.TimeUnit;
diff --git a/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsSampledSpanBenchmark.java b/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsSampledSpanBenchmark.java
index 492ee089..57e41136 100644
--- a/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsSampledSpanBenchmark.java
+++ b/benchmarks/src/jmh/java/io/opencensus/trace/RecordTraceEventsSampledSpanBenchmark.java
@@ -13,7 +13,7 @@
 
 package io.opencensus.trace;
 
-import io.opencensus.impl.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl;
 import io.opencensus.trace.samplers.Samplers;
 import java.util.HashMap;
 import java.util.concurrent.TimeUnit;
diff --git a/benchmarks/src/jmh/java/io/opencensus/trace/StartEndSpanBenchmark.java b/benchmarks/src/jmh/java/io/opencensus/trace/StartEndSpanBenchmark.java
index 8eebf032..0daa6c1d 100644
--- a/benchmarks/src/jmh/java/io/opencensus/trace/StartEndSpanBenchmark.java
+++ b/benchmarks/src/jmh/java/io/opencensus/trace/StartEndSpanBenchmark.java
@@ -13,7 +13,7 @@
 
 package io.opencensus.trace;
 
-import io.opencensus.impl.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl;
 import io.opencensus.trace.samplers.Samplers;
 import java.util.concurrent.TimeUnit;
 import org.openjdk.jmh.annotations.Benchmark;
diff --git a/benchmarks/src/jmh/java/io/opencensus/trace/propagation/BinaryPropagationImplBenchmark.java b/benchmarks/src/jmh/java/io/opencensus/trace/propagation/BinaryPropagationImplBenchmark.java
index 4978e8c2..fa82dbac 100644
--- a/benchmarks/src/jmh/java/io/opencensus/trace/propagation/BinaryPropagationImplBenchmark.java
+++ b/benchmarks/src/jmh/java/io/opencensus/trace/propagation/BinaryPropagationImplBenchmark.java
@@ -13,7 +13,7 @@
 
 package io.opencensus.trace.propagation;
 
-import io.opencensus.impl.trace.propagation.BinaryFormatImpl;
+import io.opencensus.implcore.trace.propagation.BinaryFormatImpl;
 import io.opencensus.trace.SpanContext;
 import io.opencensus.trace.SpanId;
 import io.opencensus.trace.TraceId;
diff --git a/core/src/main/java/io/opencensus/stats/Stats.java b/core/src/main/java/io/opencensus/stats/Stats.java
index 9d943758..0d30c58b 100644
--- a/core/src/main/java/io/opencensus/stats/Stats.java
+++ b/core/src/main/java/io/opencensus/stats/Stats.java
@@ -56,7 +56,7 @@ public final class Stats {
     try {
       // Call Class.forName with literal string name of the class to help shading tools.
       return Provider.createInstance(
-          Class.forName("io.opencensus.impl.stats.StatsComponentImplLite", true, classLoader),
+          Class.forName("io.opencensus.impllite.stats.StatsComponentImplLite", true, classLoader),
           StatsComponent.class);
     } catch (ClassNotFoundException e) {
       logger.log(
diff --git a/core/src/main/java/io/opencensus/tags/Tags.java b/core/src/main/java/io/opencensus/tags/Tags.java
index 19190c85..06c4cf4a 100644
--- a/core/src/main/java/io/opencensus/tags/Tags.java
+++ b/core/src/main/java/io/opencensus/tags/Tags.java
@@ -63,7 +63,7 @@ public final class Tags {
     try {
       // Call Class.forName with literal string name of the class to help shading tools.
       return Provider.createInstance(
-          Class.forName("io.opencensus.impl.tags.TagsComponentImplLite", true, classLoader),
+          Class.forName("io.opencensus.impllite.tags.TagsComponentImplLite", true, classLoader),
           TagsComponent.class);
     } catch (ClassNotFoundException e) {
       logger.log(
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/MeasureToViewMap.java b/core_impl/src/main/java/io/opencensus/implcore/stats/MeasureToViewMap.java
index 9162ad68..6ca3a701 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/MeasureToViewMap.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/MeasureToViewMap.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimap;
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/MutableAggregation.java b/core_impl/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java
index e5666c80..1b34823b 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/MutableAggregation.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/MutableViewData.java b/core_impl/src/main/java/io/opencensus/implcore/stats/MutableViewData.java
index 73bd5231..1bef7375 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/MutableViewData.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/MutableViewData.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
@@ -20,13 +20,13 @@ import io.opencensus.common.Clock;
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
 import io.opencensus.common.Timestamp;
-import io.opencensus.impl.stats.MutableAggregation.MutableCount;
-import io.opencensus.impl.stats.MutableAggregation.MutableHistogram;
-import io.opencensus.impl.stats.MutableAggregation.MutableMean;
-import io.opencensus.impl.stats.MutableAggregation.MutableRange;
-import io.opencensus.impl.stats.MutableAggregation.MutableStdDev;
-import io.opencensus.impl.stats.MutableAggregation.MutableSum;
-import io.opencensus.impl.tags.TagContextImpl;
+import io.opencensus.implcore.stats.MutableAggregation.MutableCount;
+import io.opencensus.implcore.stats.MutableAggregation.MutableHistogram;
+import io.opencensus.implcore.stats.MutableAggregation.MutableMean;
+import io.opencensus.implcore.stats.MutableAggregation.MutableRange;
+import io.opencensus.implcore.stats.MutableAggregation.MutableStdDev;
+import io.opencensus.implcore.stats.MutableAggregation.MutableSum;
+import io.opencensus.implcore.tags.TagContextImpl;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Histogram;
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/StatsComponentImplBase.java b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsComponentImplBase.java
index d0f9d869..10339345 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/StatsComponentImplBase.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsComponentImplBase.java
@@ -11,19 +11,25 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import io.opencensus.common.Clock;
-import io.opencensus.impl.internal.EventQueue;
+import io.opencensus.implcore.internal.EventQueue;
 import io.opencensus.stats.StatsComponent;
 
 /** Base implementation of {@link StatsComponent}. */
-class StatsComponentImplBase extends StatsComponent {
+public class StatsComponentImplBase extends StatsComponent {
 
   private final ViewManagerImpl viewManager;
   private final StatsRecorderImpl statsRecorder;
 
-  StatsComponentImplBase(EventQueue queue, Clock clock) {
+  /**
+   * Creates a new {@code StatsComponentImplBase}.
+   *
+   * @param queue the queue implementation.
+   * @param clock the clock to use when recording stats.
+   */
+  public StatsComponentImplBase(EventQueue queue, Clock clock) {
     StatsManager statsManager = new StatsManager(queue, clock);
     this.viewManager = new ViewManagerImpl(statsManager);
     this.statsRecorder = new StatsRecorderImpl(statsManager);
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/StatsManager.java b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsManager.java
index 4094f495..5313e3c6 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/StatsManager.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsManager.java
@@ -11,10 +11,10 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import io.opencensus.common.Clock;
-import io.opencensus.impl.internal.EventQueue;
+import io.opencensus.implcore.internal.EventQueue;
 import io.opencensus.stats.MeasureMap;
 import io.opencensus.stats.View;
 import io.opencensus.stats.ViewData;
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/StatsRecorderImpl.java b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsRecorderImpl.java
index d7e9b084..9d85c8d7 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/StatsRecorderImpl.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/StatsRecorderImpl.java
@@ -11,14 +11,14 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import io.opencensus.stats.MeasureMap;
 import io.opencensus.stats.StatsRecorder;
 import io.opencensus.tags.TagContext;
 
 /** Implementation of {@link StatsRecorder}. */
-final class StatsRecorderImpl extends StatsRecorder {
+public final class StatsRecorderImpl extends StatsRecorder {
   private final StatsManager statsManager;
 
   StatsRecorderImpl(StatsManager statsManager) {
diff --git a/core_impl/src/main/java/io/opencensus/impl/stats/ViewManagerImpl.java b/core_impl/src/main/java/io/opencensus/implcore/stats/ViewManagerImpl.java
index 60292611..95ad5766 100644
--- a/core_impl/src/main/java/io/opencensus/impl/stats/ViewManagerImpl.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/stats/ViewManagerImpl.java
@@ -11,14 +11,14 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import io.opencensus.stats.View;
 import io.opencensus.stats.ViewData;
 import io.opencensus.stats.ViewManager;
 
 /** Implementation of {@link ViewManager}. */
-final class ViewManagerImpl extends ViewManager {
+public final class ViewManagerImpl extends ViewManager {
   private final StatsManager statsManager;
 
   ViewManagerImpl(StatsManager statsManager) {
diff --git a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextBuilderImpl.java b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextBuilderImpl.java
index 5b0de78e..e523b950 100644
--- a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextBuilderImpl.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextBuilderImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
diff --git a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextImpl.java b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextImpl.java
index 658a48cf..0c65a6a6 100644
--- a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextImpl.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
diff --git a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextUtils.java b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextUtils.java
index 58561fd8..c46c98d7 100644
--- a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextUtils.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextUtils.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
diff --git a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextsImpl.java b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextsImpl.java
index 3d182ecf..32ae25b1 100644
--- a/core_impl/src/main/java/io/opencensus/impl/tags/TagContextsImpl.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/tags/TagContextsImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import io.opencensus.tags.Tag;
 import io.opencensus.tags.TagContext;
diff --git a/core_impl/src/main/java/io/opencensus/impl/tags/TagsComponentImplBase.java b/core_impl/src/main/java/io/opencensus/implcore/tags/TagsComponentImplBase.java
index c1cb50e8..ec079b3a 100644
--- a/core_impl/src/main/java/io/opencensus/impl/tags/TagsComponentImplBase.java
+++ b/core_impl/src/main/java/io/opencensus/implcore/tags/TagsComponentImplBase.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import io.opencensus.tags.TagContexts;
 import io.opencensus.tags.TagPropagationComponent;
diff --git a/core_impl/src/test/java/io/opencensus/impl/stats/MeasureToViewMapTest.java b/core_impl/src/test/java/io/opencensus/implcore/stats/MeasureToViewMapTest.java
index 91031cbb..040a28f3 100644
--- a/core_impl/src/test/java/io/opencensus/impl/stats/MeasureToViewMapTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/stats/MeasureToViewMapTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/core_impl/src/test/java/io/opencensus/impl/stats/MutableAggregationTest.java b/core_impl/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java
index 2d642fb8..44c27c77 100644
--- a/core_impl/src/test/java/io/opencensus/impl/stats/MutableAggregationTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java
@@ -11,17 +11,17 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import io.opencensus.common.Function;
-import io.opencensus.impl.stats.MutableAggregation.MutableCount;
-import io.opencensus.impl.stats.MutableAggregation.MutableHistogram;
-import io.opencensus.impl.stats.MutableAggregation.MutableMean;
-import io.opencensus.impl.stats.MutableAggregation.MutableRange;
-import io.opencensus.impl.stats.MutableAggregation.MutableStdDev;
-import io.opencensus.impl.stats.MutableAggregation.MutableSum;
+import io.opencensus.implcore.stats.MutableAggregation.MutableCount;
+import io.opencensus.implcore.stats.MutableAggregation.MutableHistogram;
+import io.opencensus.implcore.stats.MutableAggregation.MutableMean;
+import io.opencensus.implcore.stats.MutableAggregation.MutableRange;
+import io.opencensus.implcore.stats.MutableAggregation.MutableStdDev;
+import io.opencensus.implcore.stats.MutableAggregation.MutableSum;
 import io.opencensus.stats.BucketBoundaries;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -32,7 +32,7 @@ import org.junit.rules.ExpectedException;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Unit tests for {@link io.opencensus.impl.stats.MutableAggregation}. */
+/** Unit tests for {@link io.opencensus.implcore.stats.MutableAggregation}. */
 @RunWith(JUnit4.class)
 public class MutableAggregationTest {
 
diff --git a/core_impl/src/test/java/io/opencensus/impl/stats/MutableViewDataTest.java b/core_impl/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java
index 1de2867e..96f15ad6 100644
--- a/core_impl/src/test/java/io/opencensus/impl/stats/MutableViewDataTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java
@@ -11,17 +11,17 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import com.google.common.collect.ImmutableMap;
-import io.opencensus.impl.stats.MutableAggregation.MutableCount;
-import io.opencensus.impl.stats.MutableAggregation.MutableHistogram;
-import io.opencensus.impl.stats.MutableAggregation.MutableMean;
-import io.opencensus.impl.stats.MutableAggregation.MutableRange;
-import io.opencensus.impl.stats.MutableAggregation.MutableStdDev;
-import io.opencensus.impl.stats.MutableAggregation.MutableSum;
+import io.opencensus.implcore.stats.MutableAggregation.MutableCount;
+import io.opencensus.implcore.stats.MutableAggregation.MutableHistogram;
+import io.opencensus.implcore.stats.MutableAggregation.MutableMean;
+import io.opencensus.implcore.stats.MutableAggregation.MutableRange;
+import io.opencensus.implcore.stats.MutableAggregation.MutableStdDev;
+import io.opencensus.implcore.stats.MutableAggregation.MutableSum;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Histogram;
 import io.opencensus.stats.Aggregation.Sum;
diff --git a/core_impl/src/test/java/io/opencensus/impl/stats/StatsTestUtil.java b/core_impl/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java
index 128fb49f..28b8c65e 100644
--- a/core_impl/src/test/java/io/opencensus/impl/stats/StatsTestUtil.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/core_impl/src/test/java/io/opencensus/impl/stats/ViewManagerImplTest.java b/core_impl/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java
index 184ff22b..bb60a574 100644
--- a/core_impl/src/test/java/io/opencensus/impl/stats/ViewManagerImplTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java
@@ -11,17 +11,17 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
-import static io.opencensus.impl.stats.StatsTestUtil.assertAggregationMapEquals;
-import static io.opencensus.impl.stats.StatsTestUtil.createAggregationData;
+import static io.opencensus.implcore.stats.StatsTestUtil.assertAggregationMapEquals;
+import static io.opencensus.implcore.stats.StatsTestUtil.createAggregationData;
 
 import com.google.common.collect.ImmutableMap;
 import io.opencensus.common.Duration;
 import io.opencensus.common.Timestamp;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.tags.TagContextsImpl;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.tags.TagContextsImpl;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Histogram;
diff --git a/core_impl/src/test/java/io/opencensus/impl/tags/TagContextImplTest.java b/core_impl/src/test/java/io/opencensus/implcore/tags/TagContextImplTest.java
index 0639e31c..a0a4b0af 100644
--- a/core_impl/src/test/java/io/opencensus/impl/tags/TagContextImplTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/tags/TagContextImplTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertFalse;
diff --git a/core_impl/src/test/java/io/opencensus/impl/tags/TagContextsImplTest.java b/core_impl/src/test/java/io/opencensus/implcore/tags/TagContextsImplTest.java
index 607e1e8e..a2b64b1d 100644
--- a/core_impl/src/test/java/io/opencensus/impl/tags/TagContextsImplTest.java
+++ b/core_impl/src/test/java/io/opencensus/implcore/tags/TagContextsImplTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.implcore.tags;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/core_impl_android/src/main/java/io/opencensus/impl/stats/StatsComponentImplLite.java b/core_impl_android/src/main/java/io/opencensus/impllite/stats/StatsComponentImplLite.java
index f0641719..55df795c 100644
--- a/core_impl_android/src/main/java/io/opencensus/impl/stats/StatsComponentImplLite.java
+++ b/core_impl_android/src/main/java/io/opencensus/impllite/stats/StatsComponentImplLite.java
@@ -11,10 +11,11 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.impllite.stats;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.stats.StatsComponentImplBase;
 import io.opencensus.stats.StatsComponent;
 
 /**
diff --git a/core_impl_android/src/main/java/io/opencensus/impl/tags/TagsComponentImplLite.java b/core_impl_android/src/main/java/io/opencensus/impllite/tags/TagsComponentImplLite.java
index 3a66d319..88aa372f 100644
--- a/core_impl_android/src/main/java/io/opencensus/impl/tags/TagsComponentImplLite.java
+++ b/core_impl_android/src/main/java/io/opencensus/impllite/tags/TagsComponentImplLite.java
@@ -11,8 +11,9 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.impllite.tags;
 
+import io.opencensus.implcore.tags.TagsComponentImplBase;
 import io.opencensus.tags.TagsComponent;
 
 /** Android-compatible implementation of {@link TagsComponent}. */
diff --git a/core_impl_android/src/test/java/io/opencensus/impl/stats/StatsTest.java b/core_impl_android/src/test/java/io/opencensus/impllite/stats/StatsTest.java
index e637b805..d0afa818 100644
--- a/core_impl_android/src/test/java/io/opencensus/impl/stats/StatsTest.java
+++ b/core_impl_android/src/test/java/io/opencensus/impllite/stats/StatsTest.java
@@ -11,10 +11,12 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.stats;
+package io.opencensus.impllite.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import io.opencensus.implcore.stats.StatsRecorderImpl;
+import io.opencensus.implcore.stats.ViewManagerImpl;
 import io.opencensus.stats.Stats;
 import io.opencensus.stats.StatsComponent;
 import org.junit.Test;
diff --git a/core_impl_android/src/test/java/io/opencensus/impl/tags/TagsTest.java b/core_impl_android/src/test/java/io/opencensus/impllite/tags/TagsTest.java
index c9f897bf..541e6584 100644
--- a/core_impl_android/src/test/java/io/opencensus/impl/tags/TagsTest.java
+++ b/core_impl_android/src/test/java/io/opencensus/impllite/tags/TagsTest.java
@@ -11,10 +11,11 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.tags;
+package io.opencensus.impllite.tags;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import io.opencensus.implcore.tags.TagContextsImpl;
 import io.opencensus.tags.Tags;
 import io.opencensus.tags.TagsComponent;
 import org.junit.Test;
diff --git a/core_impl_java/src/main/java/io/opencensus/impl/stats/StatsComponentImpl.java b/core_impl_java/src/main/java/io/opencensus/impl/stats/StatsComponentImpl.java
index 461a6a2b..deb0f07d 100644
--- a/core_impl_java/src/main/java/io/opencensus/impl/stats/StatsComponentImpl.java
+++ b/core_impl_java/src/main/java/io/opencensus/impl/stats/StatsComponentImpl.java
@@ -13,8 +13,9 @@
 
 package io.opencensus.impl.stats;
 
-import io.opencensus.impl.common.MillisClock;
 import io.opencensus.impl.internal.DisruptorEventQueue;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.stats.StatsComponentImplBase;
 import io.opencensus.stats.StatsComponent;
 
 /** Java 7 and 8 implementation of {@link StatsComponent}. */
diff --git a/core_impl_java/src/main/java/io/opencensus/impl/tags/TagsComponentImpl.java b/core_impl_java/src/main/java/io/opencensus/impl/tags/TagsComponentImpl.java
index c360ae60..a7c32667 100644
--- a/core_impl_java/src/main/java/io/opencensus/impl/tags/TagsComponentImpl.java
+++ b/core_impl_java/src/main/java/io/opencensus/impl/tags/TagsComponentImpl.java
@@ -13,6 +13,7 @@
 
 package io.opencensus.impl.tags;
 
+import io.opencensus.implcore.tags.TagsComponentImplBase;
 import io.opencensus.tags.TagsComponent;
 
 /** Java 7 and 8 implementation of {@link TagsComponent}. */
diff --git a/core_impl_java/src/test/java/io/opencensus/impl/stats/StatsTest.java b/core_impl_java/src/test/java/io/opencensus/impl/stats/StatsTest.java
index 36ff3e79..c8892c1b 100644
--- a/core_impl_java/src/test/java/io/opencensus/impl/stats/StatsTest.java
+++ b/core_impl_java/src/test/java/io/opencensus/impl/stats/StatsTest.java
@@ -15,6 +15,8 @@ package io.opencensus.impl.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import io.opencensus.implcore.stats.StatsRecorderImpl;
+import io.opencensus.implcore.stats.ViewManagerImpl;
 import io.opencensus.stats.Stats;
 import io.opencensus.stats.StatsComponent;
 import org.junit.Test;
diff --git a/core_impl_java/src/test/java/io/opencensus/impl/tags/TagsTest.java b/core_impl_java/src/test/java/io/opencensus/impl/tags/TagsTest.java
index c9f897bf..661e463a 100644
--- a/core_impl_java/src/test/java/io/opencensus/impl/tags/TagsTest.java
+++ b/core_impl_java/src/test/java/io/opencensus/impl/tags/TagsTest.java
@@ -15,6 +15,7 @@ package io.opencensus.impl.tags;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import io.opencensus.implcore.tags.TagContextsImpl;
 import io.opencensus.tags.Tags;
 import io.opencensus.tags.TagsComponent;
 import org.junit.Test;
diff --git a/impl/src/main/java/io/opencensus/impl/internal/DisruptorEventQueue.java b/impl/src/main/java/io/opencensus/impl/internal/DisruptorEventQueue.java
index be2d422e..77479ea3 100644
--- a/impl/src/main/java/io/opencensus/impl/internal/DisruptorEventQueue.java
+++ b/impl/src/main/java/io/opencensus/impl/internal/DisruptorEventQueue.java
@@ -19,7 +19,7 @@ import com.lmax.disruptor.RingBuffer;
 import com.lmax.disruptor.SleepingWaitStrategy;
 import com.lmax.disruptor.dsl.Disruptor;
 import com.lmax.disruptor.dsl.ProducerType;
-import io.opencensus.impl.internal.EventQueue;
+import io.opencensus.implcore.internal.EventQueue;
 import java.util.concurrent.Executors;
 import javax.annotation.concurrent.ThreadSafe;
 
diff --git a/impl/src/main/java/io/opencensus/impl/trace/TraceComponentImpl.java b/impl/src/main/java/io/opencensus/impl/trace/TraceComponentImpl.java
index 8457adfc..7e1397eb 100644
--- a/impl/src/main/java/io/opencensus/impl/trace/TraceComponentImpl.java
+++ b/impl/src/main/java/io/opencensus/impl/trace/TraceComponentImpl.java
@@ -13,10 +13,10 @@
 
 package io.opencensus.impl.trace;
 
-import io.opencensus.impl.common.MillisClock;
 import io.opencensus.impl.internal.DisruptorEventQueue;
-import io.opencensus.impl.trace.TraceComponentImplBase;
 import io.opencensus.impl.trace.internal.ThreadLocalRandomHandler;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.trace.TraceComponentImplBase;
 import io.opencensus.trace.TraceComponent;
 
 /** Java 7 and 8 implementation of the {@link TraceComponent}. */
diff --git a/impl/src/main/java/io/opencensus/impl/trace/internal/ThreadLocalRandomHandler.java b/impl/src/main/java/io/opencensus/impl/trace/internal/ThreadLocalRandomHandler.java
index 6094167f..34acf8f7 100644
--- a/impl/src/main/java/io/opencensus/impl/trace/internal/ThreadLocalRandomHandler.java
+++ b/impl/src/main/java/io/opencensus/impl/trace/internal/ThreadLocalRandomHandler.java
@@ -13,7 +13,7 @@
 
 package io.opencensus.impl.trace.internal;
 
-import io.opencensus.impl.trace.internal.RandomHandler;
+import io.opencensus.implcore.trace.internal.RandomHandler;
 import java.util.Random;
 import java.util.concurrent.ThreadLocalRandom;
 import javax.annotation.concurrent.ThreadSafe;
diff --git a/impl/src/main/java/io/opencensus/trace/TraceComponentImpl.java b/impl/src/main/java/io/opencensus/trace/TraceComponentImpl.java
index 211e08d9..a4c79241 100644
--- a/impl/src/main/java/io/opencensus/trace/TraceComponentImpl.java
+++ b/impl/src/main/java/io/opencensus/trace/TraceComponentImpl.java
@@ -13,10 +13,10 @@
 
 package io.opencensus.trace;
 
-import io.opencensus.impl.common.MillisClock;
 import io.opencensus.impl.internal.DisruptorEventQueue;
-import io.opencensus.impl.trace.TraceComponentImplBase;
 import io.opencensus.impl.trace.internal.ThreadLocalRandomHandler;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.trace.TraceComponentImplBase;
 
 /** Java 7 and 8 implementation of the {@link TraceComponent}. */
 // TraceComponentImpl was moved to io.opencensus.impl.trace. This class exists for backwards
diff --git a/impl/src/test/java/io/opencensus/impl/internal/DisruptorEventQueueTest.java b/impl/src/test/java/io/opencensus/impl/internal/DisruptorEventQueueTest.java
index 2be9eecb..b95314f9 100644
--- a/impl/src/test/java/io/opencensus/impl/internal/DisruptorEventQueueTest.java
+++ b/impl/src/test/java/io/opencensus/impl/internal/DisruptorEventQueueTest.java
@@ -16,7 +16,7 @@ package io.opencensus.impl.internal;
 import static com.google.common.truth.Truth.assertThat;
 
 import io.opencensus.impl.internal.DisruptorEventQueue;
-import io.opencensus.impl.internal.EventQueue;
+import io.opencensus.implcore.internal.EventQueue;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
diff --git a/impl/src/test/java/io/opencensus/impl/trace/TracingTest.java b/impl/src/test/java/io/opencensus/impl/trace/TracingTest.java
index 5c0ca65a..8bdb9433 100644
--- a/impl/src/test/java/io/opencensus/impl/trace/TracingTest.java
+++ b/impl/src/test/java/io/opencensus/impl/trace/TracingTest.java
@@ -15,8 +15,9 @@ package io.opencensus.impl.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.trace.export.ExportComponentImpl;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.trace.TracerImpl;
+import io.opencensus.implcore.trace.export.ExportComponentImpl;
 import io.opencensus.trace.TraceComponent;
 import io.opencensus.trace.Tracing;
 import io.opencensus.trace.propagation.PropagationComponent;
diff --git a/impl_core/src/main/java/io/opencensus/impl/common/MillisClock.java b/impl_core/src/main/java/io/opencensus/implcore/common/MillisClock.java
index 50f03d48..2630db2d 100644
--- a/impl_core/src/main/java/io/opencensus/impl/common/MillisClock.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/common/MillisClock.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.common;
+package io.opencensus.implcore.common;
 
 import io.opencensus.common.Clock;
 import io.opencensus.common.Timestamp;
diff --git a/impl_core/src/main/java/io/opencensus/impl/internal/EventQueue.java b/impl_core/src/main/java/io/opencensus/implcore/internal/EventQueue.java
index a7ef7581..8f09c3c2 100644
--- a/impl_core/src/main/java/io/opencensus/impl/internal/EventQueue.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/internal/EventQueue.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.internal;
+package io.opencensus.implcore.internal;
 
 /** A queue that processes events. See {@code DisruptorEventQueue} for an example. */
 public interface EventQueue {
diff --git a/impl_core/src/main/java/io/opencensus/impl/internal/SimpleEventQueue.java b/impl_core/src/main/java/io/opencensus/implcore/internal/SimpleEventQueue.java
index 27481cac..68a31905 100644
--- a/impl_core/src/main/java/io/opencensus/impl/internal/SimpleEventQueue.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/internal/SimpleEventQueue.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.internal;
+package io.opencensus.implcore.internal;
 
 /**
  * An {@link EventQueue} that processes events in the current thread. This class can be used for
diff --git a/impl_core/src/main/java/io/opencensus/impl/internal/TimestampConverter.java b/impl_core/src/main/java/io/opencensus/implcore/internal/TimestampConverter.java
index 02f0266e..d1c52c4b 100644
--- a/impl_core/src/main/java/io/opencensus/impl/internal/TimestampConverter.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/internal/TimestampConverter.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.internal;
+package io.opencensus.implcore.internal;
 
 import io.opencensus.common.Clock;
 import io.opencensus.common.Timestamp;
diff --git a/impl_core/src/main/java/io/opencensus/impl/internal/VarInt.java b/impl_core/src/main/java/io/opencensus/implcore/internal/VarInt.java
index 1b7fc265..cf614f1d 100644
--- a/impl_core/src/main/java/io/opencensus/impl/internal/VarInt.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/internal/VarInt.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.internal;
+package io.opencensus.implcore.internal;
 
 import java.io.IOException;
 import java.io.InputStream;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/SpanBuilderImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java
index 2bef6540..21bc3757 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/SpanBuilderImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanBuilderImpl.java
@@ -11,13 +11,13 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import io.opencensus.common.Clock;
-import io.opencensus.impl.internal.TimestampConverter;
-import io.opencensus.impl.trace.internal.RandomHandler;
+import io.opencensus.implcore.internal.TimestampConverter;
+import io.opencensus.implcore.trace.internal.RandomHandler;
 import io.opencensus.trace.Link;
 import io.opencensus.trace.Link.Type;
 import io.opencensus.trace.Sampler;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/SpanImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java
index d2a66609..fbc753f5 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/SpanImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/SpanImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
@@ -19,8 +19,8 @@ import static com.google.common.base.Preconditions.checkState;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.EvictingQueue;
 import io.opencensus.common.Clock;
-import io.opencensus.impl.internal.TimestampConverter;
-import io.opencensus.impl.trace.internal.ConcurrentIntrusiveList.Element;
+import io.opencensus.implcore.internal.TimestampConverter;
+import io.opencensus.implcore.trace.internal.ConcurrentIntrusiveList.Element;
 import io.opencensus.trace.Annotation;
 import io.opencensus.trace.AttributeValue;
 import io.opencensus.trace.EndSpanOptions;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/StartEndHandlerImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/StartEndHandlerImpl.java
index 162871dd..76276cd7 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/StartEndHandlerImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/StartEndHandlerImpl.java
@@ -11,13 +11,13 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
-import io.opencensus.impl.internal.EventQueue;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.export.RunningSpanStoreImpl;
-import io.opencensus.impl.trace.export.SampledSpanStoreImpl;
-import io.opencensus.impl.trace.export.SpanExporterImpl;
+import io.opencensus.implcore.internal.EventQueue;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.export.RunningSpanStoreImpl;
+import io.opencensus.implcore.trace.export.SampledSpanStoreImpl;
+import io.opencensus.implcore.trace.export.SpanExporterImpl;
 import io.opencensus.trace.Span.Options;
 import io.opencensus.trace.export.SpanData;
 import javax.annotation.Nullable;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/TraceComponentImplBase.java b/impl_core/src/main/java/io/opencensus/implcore/trace/TraceComponentImplBase.java
index b4a6c3d3..8c16950d 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/TraceComponentImplBase.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/TraceComponentImplBase.java
@@ -11,16 +11,16 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import io.opencensus.common.Clock;
-import io.opencensus.impl.internal.EventQueue;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.config.TraceConfigImpl;
-import io.opencensus.impl.trace.export.ExportComponentImpl;
-import io.opencensus.impl.trace.internal.RandomHandler;
-import io.opencensus.impl.trace.propagation.PropagationComponentImpl;
+import io.opencensus.implcore.internal.EventQueue;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.config.TraceConfigImpl;
+import io.opencensus.implcore.trace.export.ExportComponentImpl;
+import io.opencensus.implcore.trace.internal.RandomHandler;
+import io.opencensus.implcore.trace.propagation.PropagationComponentImpl;
 import io.opencensus.trace.TraceComponent;
 import io.opencensus.trace.Tracer;
 import io.opencensus.trace.config.TraceConfig;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/TracerImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/TracerImpl.java
index 735fdca1..0da79120 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/TracerImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/TracerImpl.java
@@ -11,10 +11,10 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import io.opencensus.common.Clock;
-import io.opencensus.impl.trace.internal.RandomHandler;
+import io.opencensus.implcore.trace.internal.RandomHandler;
 import io.opencensus.trace.Span;
 import io.opencensus.trace.SpanBuilder;
 import io.opencensus.trace.SpanContext;
@@ -23,10 +23,10 @@ import io.opencensus.trace.config.TraceConfig;
 import javax.annotation.Nullable;
 
 /** Implementation of the {@link Tracer}. */
-final class TracerImpl extends Tracer {
+public final class TracerImpl extends Tracer {
   private final SpanBuilderImpl.Options spanBuilderOptions;
 
-  TracerImpl(
+  public TracerImpl(
       RandomHandler randomHandler,
       SpanImpl.StartEndHandler startEndHandler,
       Clock clock,
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/config/TraceConfigImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/config/TraceConfigImpl.java
index 0973acdc..1f14226b 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/config/TraceConfigImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/config/TraceConfigImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.config;
+package io.opencensus.implcore.trace.config;
 
 import io.opencensus.trace.config.TraceConfig;
 import io.opencensus.trace.config.TraceParams;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/export/ExportComponentImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/export/ExportComponentImpl.java
index 826c5a72..ac0f8087 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/export/ExportComponentImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/export/ExportComponentImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import io.opencensus.trace.export.ExportComponent;
 import io.opencensus.trace.export.RunningSpanStore;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/export/RunningSpanStoreImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/export/RunningSpanStoreImpl.java
index 04628767..a793644a 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/export/RunningSpanStoreImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/export/RunningSpanStoreImpl.java
@@ -11,10 +11,10 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
-import io.opencensus.impl.trace.SpanImpl;
-import io.opencensus.impl.trace.internal.ConcurrentIntrusiveList;
+import io.opencensus.implcore.trace.SpanImpl;
+import io.opencensus.implcore.trace.internal.ConcurrentIntrusiveList;
 import io.opencensus.trace.export.RunningSpanStore;
 import io.opencensus.trace.export.SpanData;
 import java.util.ArrayList;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/export/SampledSpanStoreImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SampledSpanStoreImpl.java
index c7532152..5331ade6 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/export/SampledSpanStoreImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SampledSpanStoreImpl.java
@@ -11,10 +11,10 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import com.google.common.collect.EvictingQueue;
-import io.opencensus.impl.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl;
 import io.opencensus.trace.Status;
 import io.opencensus.trace.Status.CanonicalCode;
 import io.opencensus.trace.export.SampledSpanStore;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/export/SpanExporterImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java
index 90d1134f..af46cf54 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/export/SpanExporterImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java
@@ -11,10 +11,10 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import com.google.common.annotations.VisibleForTesting;
-import io.opencensus.impl.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl;
 import io.opencensus.trace.export.ExportComponent;
 import io.opencensus.trace.export.SpanData;
 import io.opencensus.trace.export.SpanExporter;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/internal/ConcurrentIntrusiveList.java b/impl_core/src/main/java/io/opencensus/implcore/trace/internal/ConcurrentIntrusiveList.java
index 09b24637..ef2388c2 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/internal/ConcurrentIntrusiveList.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/internal/ConcurrentIntrusiveList.java
@@ -11,11 +11,11 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.internal;
+package io.opencensus.implcore.trace.internal;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
-import io.opencensus.impl.trace.internal.ConcurrentIntrusiveList.Element;
+import io.opencensus.implcore.trace.internal.ConcurrentIntrusiveList.Element;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/internal/RandomHandler.java b/impl_core/src/main/java/io/opencensus/implcore/trace/internal/RandomHandler.java
index 3ce4502f..702bd474 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/internal/RandomHandler.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/internal/RandomHandler.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.internal;
+package io.opencensus.implcore.trace.internal;
 
 import java.security.SecureRandom;
 import java.util.Random;
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/propagation/BinaryFormatImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/propagation/BinaryFormatImpl.java
index ecf69695..0aa70189 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/propagation/BinaryFormatImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/propagation/BinaryFormatImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.propagation;
+package io.opencensus.implcore.trace.propagation;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
diff --git a/impl_core/src/main/java/io/opencensus/impl/trace/propagation/PropagationComponentImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/propagation/PropagationComponentImpl.java
index 755ba276..b090ab76 100644
--- a/impl_core/src/main/java/io/opencensus/impl/trace/propagation/PropagationComponentImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/propagation/PropagationComponentImpl.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.propagation;
+package io.opencensus.implcore.trace.propagation;
 
 import io.opencensus.trace.propagation.BinaryFormat;
 import io.opencensus.trace.propagation.PropagationComponent;
diff --git a/impl_core/src/test/java/io/opencensus/impl/internal/TimestampConverterTest.java b/impl_core/src/test/java/io/opencensus/implcore/internal/TimestampConverterTest.java
index e87f8cc3..44a41286 100644
--- a/impl_core/src/test/java/io/opencensus/impl/internal/TimestampConverterTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/internal/TimestampConverterTest.java
@@ -11,14 +11,14 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.internal;
+package io.opencensus.implcore.internal;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Mockito.when;
 
 import io.opencensus.common.Clock;
 import io.opencensus.common.Timestamp;
-import io.opencensus.impl.internal.TimestampConverter;
+import io.opencensus.implcore.internal.TimestampConverter;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/SpanBuilderImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/SpanBuilderImplTest.java
index 7dccf2c7..98390898 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/SpanBuilderImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/SpanBuilderImplTest.java
@@ -11,13 +11,13 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Mockito.when;
 
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.internal.RandomHandler;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.internal.RandomHandler;
 import io.opencensus.testing.common.TestClock;
 import io.opencensus.trace.Span;
 import io.opencensus.trace.Span.Options;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/SpanImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/SpanImplTest.java
index 92fb62a0..bc9a9340 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/SpanImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/SpanImplTest.java
@@ -11,14 +11,14 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import io.opencensus.common.Duration;
 import io.opencensus.common.Timestamp;
-import io.opencensus.impl.internal.TimestampConverter;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.internal.TimestampConverter;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
 import io.opencensus.testing.common.TestClock;
 import io.opencensus.trace.Annotation;
 import io.opencensus.trace.AttributeValue;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/TraceComponentImplBaseTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/TraceComponentImplBaseTest.java
index 6d4f2499..4bfa1c13 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/TraceComponentImplBaseTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/TraceComponentImplBaseTest.java
@@ -11,17 +11,17 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.TraceComponentImplBase;
-import io.opencensus.impl.trace.TracerImpl;
-import io.opencensus.impl.trace.export.ExportComponentImpl;
-import io.opencensus.impl.trace.internal.RandomHandler.SecureRandomHandler;
-import io.opencensus.impl.trace.propagation.PropagationComponentImpl;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.TraceComponentImplBase;
+import io.opencensus.implcore.trace.TracerImpl;
+import io.opencensus.implcore.trace.export.ExportComponentImpl;
+import io.opencensus.implcore.trace.internal.RandomHandler.SecureRandomHandler;
+import io.opencensus.implcore.trace.propagation.PropagationComponentImpl;
 import io.opencensus.trace.TraceComponent;
 import org.junit.Test;
 import org.junit.runner.RunWith;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/TracerImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/TracerImplTest.java
index 3524e15a..453fab51 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/TracerImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/TracerImplTest.java
@@ -11,12 +11,12 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.implcore.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.internal.RandomHandler.SecureRandomHandler;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.internal.RandomHandler.SecureRandomHandler;
 import io.opencensus.testing.common.TestClock;
 import io.opencensus.trace.BlankSpan;
 import io.opencensus.trace.SpanBuilder;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/config/TraceConfigImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/config/TraceConfigImplTest.java
index 56372985..44161d0b 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/config/TraceConfigImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/config/TraceConfigImplTest.java
@@ -11,11 +11,11 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.config;
+package io.opencensus.implcore.trace.config;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.trace.config.TraceConfigImpl;
+import io.opencensus.implcore.trace.config.TraceConfigImpl;
 import io.opencensus.trace.config.TraceParams;
 import io.opencensus.trace.samplers.Samplers;
 import org.junit.Test;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/export/ExportComponentImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/export/ExportComponentImplTest.java
index 01331a45..8840fc4c 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/export/ExportComponentImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/export/ExportComponentImplTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/export/RunningSpanStoreImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/export/RunningSpanStoreImplTest.java
index 7bae1d46..3993b9a8 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/export/RunningSpanStoreImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/export/RunningSpanStoreImplTest.java
@@ -11,15 +11,15 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.SpanImpl;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.StartEndHandlerImpl;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.StartEndHandlerImpl;
 import io.opencensus.trace.Span.Options;
 import io.opencensus.trace.SpanContext;
 import io.opencensus.trace.SpanId;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/export/SampledSpanStoreImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/export/SampledSpanStoreImplTest.java
index 41912014..d44c9d9d 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/export/SampledSpanStoreImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/export/SampledSpanStoreImplTest.java
@@ -11,14 +11,14 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import io.opencensus.common.Duration;
 import io.opencensus.common.Timestamp;
-import io.opencensus.impl.trace.SpanImpl;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
 import io.opencensus.testing.common.TestClock;
 import io.opencensus.trace.EndSpanOptions;
 import io.opencensus.trace.Span;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/export/SpanExporterImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/export/SpanExporterImplTest.java
index 1b337ef7..ed7416c1 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/export/SpanExporterImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/export/SpanExporterImplTest.java
@@ -11,17 +11,17 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.export;
+package io.opencensus.implcore.trace.export;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Matchers.anyListOf;
 import static org.mockito.Mockito.doThrow;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.SpanImpl;
-import io.opencensus.impl.trace.SpanImpl.StartEndHandler;
-import io.opencensus.impl.trace.StartEndHandlerImpl;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.SpanImpl;
+import io.opencensus.implcore.trace.SpanImpl.StartEndHandler;
+import io.opencensus.implcore.trace.StartEndHandlerImpl;
 import io.opencensus.trace.Span.Options;
 import io.opencensus.trace.SpanContext;
 import io.opencensus.trace.SpanId;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/internal/ConcurrentIntrusiveListTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/internal/ConcurrentIntrusiveListTest.java
index 77574e8f..b41adb5e 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/internal/ConcurrentIntrusiveListTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/internal/ConcurrentIntrusiveListTest.java
@@ -11,12 +11,12 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.internal;
+package io.opencensus.implcore.trace.internal;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.trace.internal.ConcurrentIntrusiveList;
-import io.opencensus.impl.trace.internal.ConcurrentIntrusiveList.Element;
+import io.opencensus.implcore.trace.internal.ConcurrentIntrusiveList;
+import io.opencensus.implcore.trace.internal.ConcurrentIntrusiveList.Element;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/propagation/BinaryFormatImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/propagation/BinaryFormatImplTest.java
index a5e8c745..16d26a73 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/propagation/BinaryFormatImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/propagation/BinaryFormatImplTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.propagation;
+package io.opencensus.implcore.trace.propagation;
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
diff --git a/impl_core/src/test/java/io/opencensus/impl/trace/propagation/PropagationComponentImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/trace/propagation/PropagationComponentImplTest.java
index c8ef0708..6024f447 100644
--- a/impl_core/src/test/java/io/opencensus/impl/trace/propagation/PropagationComponentImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/trace/propagation/PropagationComponentImplTest.java
@@ -11,7 +11,7 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace.propagation;
+package io.opencensus.implcore.trace.propagation;
 
 import static com.google.common.truth.Truth.assertThat;
 
diff --git a/impl_lite/src/main/java/io/opencensus/impl/trace/TraceComponentImplLite.java b/impl_lite/src/main/java/io/opencensus/impllite/trace/TraceComponentImplLite.java
index 7b172279..b2947429 100644
--- a/impl_lite/src/main/java/io/opencensus/impl/trace/TraceComponentImplLite.java
+++ b/impl_lite/src/main/java/io/opencensus/impllite/trace/TraceComponentImplLite.java
@@ -11,11 +11,12 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.impllite.trace;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.internal.RandomHandler.SecureRandomHandler;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.TraceComponentImplBase;
+import io.opencensus.implcore.trace.internal.RandomHandler.SecureRandomHandler;
 import io.opencensus.trace.TraceComponent;
 
 /** Android-compatible implementation of the {@link TraceComponent}. */
diff --git a/impl_lite/src/main/java/io/opencensus/trace/TraceComponentImplLite.java b/impl_lite/src/main/java/io/opencensus/trace/TraceComponentImplLite.java
index 38a49927..0da3afb2 100644
--- a/impl_lite/src/main/java/io/opencensus/trace/TraceComponentImplLite.java
+++ b/impl_lite/src/main/java/io/opencensus/trace/TraceComponentImplLite.java
@@ -13,10 +13,10 @@
 
 package io.opencensus.trace;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.internal.SimpleEventQueue;
-import io.opencensus.impl.trace.TraceComponentImplBase;
-import io.opencensus.impl.trace.internal.RandomHandler.SecureRandomHandler;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.trace.TraceComponentImplBase;
+import io.opencensus.implcore.trace.internal.RandomHandler.SecureRandomHandler;
 
 /** Android-compatible implementation of the {@link TraceComponent}. */
 // TraceComponentImplLite was moved to io.opencensus.impl.trace. This class exists for backwards
diff --git a/impl_lite/src/test/java/io/opencensus/impl/trace/TraceComponentImplLiteTest.java b/impl_lite/src/test/java/io/opencensus/impllite/trace/TraceComponentImplLiteTest.java
index c07e0683..e8369fe3 100644
--- a/impl_lite/src/test/java/io/opencensus/impl/trace/TraceComponentImplLiteTest.java
+++ b/impl_lite/src/test/java/io/opencensus/impllite/trace/TraceComponentImplLiteTest.java
@@ -11,13 +11,15 @@
  * limitations under the License.
  */
 
-package io.opencensus.impl.trace;
+package io.opencensus.impllite.trace;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import io.opencensus.impl.common.MillisClock;
-import io.opencensus.impl.trace.export.ExportComponentImpl;
-import io.opencensus.impl.trace.propagation.PropagationComponentImpl;
+import io.opencensus.implcore.common.MillisClock;
+import io.opencensus.implcore.trace.TracerImpl;
+import io.opencensus.implcore.trace.export.ExportComponentImpl;
+import io.opencensus.implcore.trace.propagation.PropagationComponentImpl;
+import io.opencensus.impllite.trace.TraceComponentImplLite;
 import io.opencensus.trace.Tracing;
 import org.junit.Test;
 import org.junit.runner.RunWith;