We're happy to announce AppHarbor integration with CodePlex -- Microsoft's open source code-hosting site. The integration is currently live on CodePlex (under "Project Summary & Details") and here's the CodePlex announcement.
We have written a short guide on how to set up your CodePlex project to deploy automatically to AppHarbor.
We are really happy with the way Mercurial support using Bitbucket has worked out for AppHarbor users, and were excited to now support Subversion, Mercurial (again), and Team Foundation Server (!) through this collaboration with CodePlex.
Go ahead and give it a whirl, and drop us a line at firstname.lastname@example.org if you encounter any problems.