The latest release of Mnemosyne is 0.1. This is essentially a proof of concept release, and is not yet ready for general use. The core of the system is in place, however, and you are encouraged to download and have a play with what is there. Have a look at SimpleSample.java as a starting point.
Distributions can be downloaded at the sourceforge download site.
Please see the change log for details of the changes in each release.