Get SVNKit source code with the svn command line client

$ svn co http://svn.svnkit.com/repos/svnkit/trunk svnkit

Go to the checked out directory

$ cd svnkit

Use [http://ant.apache.org ANT] to build svnkit.jar

$ ant build-standalone

svnkit/lib directory will contain a library jar file (svnkit.jar) built and the Ganymed library jar (ganymed.jar) that is needed if you are going to use svn+ssh connection protocol.