GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS). As such, it aims to contain the complete functionality of JTS in C++. This includes all the OpenGIS "Simple Features for SQL" spatial predicate functions and spatial operators, as well as specific JTS enhanced topology functions. By default, the script does not build nor run the tests. You can use the option TESTBUILD=YES to build and run the tests before the make install part.