SharpDevelop currently comes with support for NUnit and offers the Gallio Addin for MBUnit. Recently Matt Ward announced the addition of MSTest support via a new add-on.
The MS Test Addin is not a replacement for Microsoft’s implementation. It uses Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll and uses the mstest.exe test runner to execute the unit tests. This means it should have full fidelity with the same tests run under Visual Studio or Team Foundation Server.
This add-on should be considered to be a transitional tool for those looking to eventually leave Visual Studio for SharpDevelop. Unlike virtually all other unit test frameworks for .NET, MSTest is only available with Visual Studio and cannot be redistributed. This may change in VS 11 when even the Express Editions are shipped with testing frameworks, but for now using MSTest makes those tests non-portable.
