The Typemock Insider blog mentions that Patterns & Practices has adopted Typemock Isolator as their mocking framework, at least for testing SharePoint applications. Blaine Wastell and Francis Cheung say they’re using it because it allows them to mock sealed and internal types, which SharePoint is full of.

I think this is cool and definitely says something: Even if you’re writing brand new code, which can be entirely designed for testability (if that’s what you want), at some point you’re going to have to interface with something you didn’t write (SharePoint, .NET Framework) and you’re still going to want to test that interface code, which is where Isolator comes in. I’m so glad they’ve got an open source license now!