The S2 Geometry Library is a spherical geometry library, very useful for manipulating regions on the sphere (commonly on Earth) and indexing geographic data.
Binaries are published on Bintray: https://bintray.com/jnegre/maven/org.jnegre.google%3As2-geometry/view
Continuous Integration provided by travis-ci.org:
Exported from code.google.com/p/s2-geometry-library-java.