Commons Collections uses Ant as its primary build system, however Maven is used for site generation.
You may also be interested in the v3.2 release notes.
To build a jar file, change into Collection's root directory and run "ant jar". The result will be in the "build" subdirectory.
All tests can be run with "ant test". A single test can be run with "ant -Dtestcase=org.apache.commons.collections.TestXxx test".
To build the Javadocs, run "ant javadoc". The result will be in "build/docs/apidocs".
To build the Javadocs, change into Collection's root directory and run "maven javadoc". The result will be in "target/docs/apidocs".
To build the full website, run "maven site". The result will be in "target/docs".