Microsoft reinventing OSS tools

David Starr wrote an open letter to Scott Guthrie from Microsoft regarding the way Microsoft deals with the open source community. Scott replied in the post's comments to some of the claims in the original post, but chose to ignore the "reinventing the wheel" issue (VSTS tests vs. NUnit, Linq vs. NHibernate...)

Scott McMaster wrote follow-up to David's post pointing to the fact Microsoft includes tests only in their Team System version, which is much more expansive than the professional edition, and I think that the main cause of the problem:
Since Microsoft charges more money for a complete solution, including unit tests, they can't charge money for an open source product, so they had to build their own testing framework instead.