README: This file should be located at the top of the OpenJDK Mercurial root repository. A full OpenJDK repository set (forest) should also include the following 7 nested repositories: "jdk", "hotspot", "langtools", "nashorn", "corba", "jaxws" and "jaxp". The root repository can be obtained with something like: hg clone http://hg.openjdk.java.net/jdk9/jdk9 openjdk9 You can run the get_source.sh script located in the root repository to get the other needed repositories: cd openjdk9 && sh ./get_source.sh People unfamiliar with Mercurial should read the first few chapters of the Mercurial book: http://hgbook.red-bean.com/read/ See http://openjdk.java.net/ for more information about OpenJDK. Simple Build Instructions: 0. Get the necessary system software/packages installed on your system, see http://hg.openjdk.java.net/jdk9/jdk9/raw-file/tip/README-builds.html 1. If you don't have a jdk8 or newer jdk, download and install it from http://java.sun.com/javase/downloads/index.jsp Add the /bin directory of this installation to your PATH environment variable. 2. Configure the build: bash ./configure 3. Build the OpenJDK: make all The resulting JDK image should be found in build/*/images/jdk where make is GNU make 3.81 or newer, /usr/bin/make on Linux usually is 3.81 or newer. Note that on Solaris, GNU make is called "gmake". Complete details are available in the file: http://hg.openjdk.java.net/jdk9/jdk9/raw-file/tip/README-builds.html