css-layout is currently in the process of big changes. If you are looking at using the latest stable version please have a look at the `deprecated` branch. This includes a js version and a C-sharp version not currently available on master.
CSSLayout is a cross platform implementation of the flexbox specification. CSSLayout targets native mobile development and is therefor disconnected from the web browser. CSSLayout is implemented in C for portability reasons and uses JNI to expose public methods to Java.
See CSSLayout/CSSLayout.h for a look at the public API being exposed.
CSSLayout builds with buck (buckbuild.com). To build run buck build //:CSSLayout and run buck test //:CSSLayout to run the test suite. For java the equivalent is buck build //:CSSLayout_java and buck test //:CSSLayout_java.
To run benchmarks run buck run //:CSSLayout:benchmark. There are currently no benchmarks for the java version.