We've opened up and documented the API for building Mingle SCM (source code management) plugins. We've also open-sourced the existing Mercurial plugin to serve as a reference implementation. The documentation is available on the Studios website. Also, if you'd like to contribute to the documentation, we've posted it to a github project.

Mingle currently provides integration for SVN, Perforce, and Mercurial. Obviously, there are many more SCM systems with which we would like to integrate. If you are hard core user of an unsupported SCM system, or perhaps you are an SCM vendor, this documentation provides you the necessary tools to build your own Mingle integration.  

If you do build a plugin we highly encourage you to share it in this space.