The Skia library is a cross-platform 2D-based renderer. The key places to look are in the folders: include/ : contains public header files src/ : contains src code The top level makefile is at the root: Android.mk These files originate from an upstream repository (skia.googlesource.com) where the project is actively developed and maintained. As a result some files are not relevant to Android, but make the merging process smoother.