File releases are available at the Sourceforge download page. The current version of Psychopyretic is 0.0.1alpha. If you want the latest source, it is recommended that you check out the SVN version (see below).
If you want to get the latest version of the source code, or you want to help develop Psychopyretic, you'll want to check out the source via Subversion. To check out the latest source via Subversion, point your Subversion client to https://psychopyretic.svn.sourceforge.net/svnroot/psychopyretic. Under Unix, you can do svn co https://psychopyretic.svn.sourceforge.net/svnroot/psychopyretic psychopyretic to check out the code and put it in the directory psychopyretic.