Microsoft and the British Library have developed a research tool based on Codeplex and running on top of Microsoft Office's SharePoint.
Source code and binaries are available for download, but to many in the free and open source software community, this type of software isn't open source or free.
Last year Richard Stallman wrote about Microsoft's CodePlex approach to "open source."
"We can see that CodePlex will encourage developers not to think about freedom," Stallman said. "It will subtly spread the idea that free software business is impossible without the support of a proprietary software company like Microsoft."
He has a point. The British Library research tool requires Microsoft's SharePoint Server 2007. That's not free and open source software.
Like many proprietary software manufacturers, Microsoft is trying to tap into the open source community without giving away too much.