There are groups all over Microsoft that are posting source for interesting little bits and pieces. These are all licensed for commerical or non-commercial modification and distribution. These came to me courtesy of Josh Ledgard. Check them out and enjoy.
I'm going to leave in the comments about the nature of "community" on each of them. It is interesting to see the split between participants and downloads (presumed users of the binary only).
VBCommenter Insert XML comments into VB code and generate the XML file when the project builds. This is probably the most mature of the projects with over 30k downloads and I’m going to estimate around 20 contributors who have submitted some code. Really about 4 non-MS people contributed very significantly and are listed as project admins. #4 on the list of GDN workspaces by their ranking system. This one is interesting, because it pairs really well with a non-MS OSS project called NDoc that takes these XML files and generates some really good HTML documentation for the code.
VSTweak Think TweakXP, but for hidden Visual Studio specific settings and registry keys. 8k downloads and one key contributor from the community here that added an entirely new section to the tool.
VSWindowManager Enables users to save window layouts in VS and reload them at a later time. Also does some cool stuff like automatically changing window layouts when you switch from Design to Code views to give the editor more space. 5k downloads and only 2-3 minor contributors from the community.
OnlineSearch Right click on a keyword in the editor and launch an MSN search for that keyword. 2k downloads and no contributors.
VSMouseBindings An often request and often cut feature that lets you assign VS commands to any of the mouse button inputs. Most commonly used to navigate backwards and forwards in the code view with the back/forward mouse keys. 2k downloads and no contributors.
VSBlogger .NET User Control and a VS Add-in which will allow you to subscribe to and read blog postings from within Visual Studio 2003. 500 downloads and no contributors. License. (Uses a different one from above. Its more recent)
VSCMDShell A toolwindow for VS that combines Cmd.Exe functionality with the ability to call VS automation commands. This functionality actually shipped in the first Alpha of VS 2005, but we cut the feature due to lack of demand and its dubious quality. I took the concept, talked to the developer, and have been working on my own implementation knowing we had no intention of ever shipping the feature. 3k downloads and 2-3 minor (bug fixing) contributors from the community.
This posting is provided "AS IS" with no warranties, and confers no rights.