Twisted is developed in a Subversion repository, but there is no reason you can't take advantage of your favorite DVCS toolchain to contribute and submit patches.
Keep in mind that unless you are a core committer, your interaction with svn basically boils down to:
# Checkout trunk svn co svn://svn.twistedmatrix.com/svn/Twisted/trunk twisted-trunk # Create patches svn diff > mypatch.patch # Keeping up-to-date with trunk: svn up
How you choose to manage your local repository is up to you, but here are a few workflows to help:
The Twisted codebase is mirrored into a set of Bazaar branches, making it easy to work on trunk or any existing branches.
See: Bazaar Workflow
There is an official Git mirror.
See: Git Workflow
There are no official Mercurial mirrors. One recommended method is to use the Mercurial MQ extension.
See: Mercurial Workflow