A brief overview is avaiable on the jmock-dev mailing-lists. http://archive.jmock.codehaus.org/dev/C991C8851C2F44518661B96E1ADF1A82%40SebastianPC and http://archive.jmock.codehaus.org/dev/FFE4A68B83E04A65AB723814EE019BF1%40SebastianPC

I am actually the only actice developer for the project.