New Python and Octave code can be submitted to the repository directly from TinkerCell. The "Save" button in TinkerCell's coding window will do the work for the user. Basically, it will generate the SVN command for uploading to the repository (the user must have subversion installed). The "tinkercelluser" sourceforge account is used for the upload process.
It is also simple for a user to submit models to the repository:
File -> Export -> Share model
The above dialog appears, asking the user for the name and family of the model. The interface at present does not allow the user to create new families of models; that will require modifying the modules.xml file and populating (correctly) the participant types and roles, which might be a bit too much for most users. So adding new families is kept as something that only more advanced users would do (and they would directly edit the xml file)