Contribute
Because Jinja is an open source project we're always open towards suggestions and patches. If you want to participate in the Jinja development python knowlege is required of corse since the project is implemented completely in python.
Development takes place on dev.pocoo.org, where the mercurial repository, tickets and development Wiki pages can be viewed.
Ways to contact the authors
Our primary communication instrument is the IRC channel #pocoo on the Freenode network. To join it, let your IRC client connect to irc.freenode.net and do /join #pocoo.
You can also join the pocoo-lib mailinglist.
If you found a bug, just open a ticket in the trac tracker. Be sure to add your e-mail address under "CC" to be notified when the issue is fixed.
The Authors
Jinja is maintained by Armin Ronacher (nickname mitsuhiko), e-mail address armin.ronacher (guess what) active-4.com.