First, RTFM to make sure what you want to do isn't already possible ;) Then, join the WebMake mailing list.

Patches can be mailed to that list, or directly to Justin (address at bottom of page).

EtText's source code is hosted at Sourceforge.

To check out the latest source, using anonymous CVS, follow the instructions on this page. modulename in this case is ettext.

If you are a frequent contributor, I can set up commit-access to the WebMake CVS for you. First, sign up to Sourceforge so you have a SourceForge user account, then mail me the username. After I set that up, you can then checkout the source using SSH (again, the modulename is ettext).

After that, you will be able to add and edit files, and commit any changes you make after that point.

Sourceforge has plenty of documentation on how to use SSH at their Sourceforge documentation site.