Fragmenting of the testing tools market?

Darrel Norton asks

Why are people creating all these new testing frameworks? Four different frameworks is at least two too many. While there might be something interesting in csUnit or MbUnit, they aren’t compelling enough for me to leave NUnit (in marketing terms these are known as switching costs). And since I’ll be using Visual Studio Team Server, I’ll very likely be using that testing framework due to all the integration work Microsoft has put into it. Why can’t we roll any functionality from the non-market leaders into the market leader (which I would assume to be NUnit, but pick one and everyone support it)? Is it pride that gets in the way? Really, the important part is to make it easier to develop better software.

I would say 4 different frameworks is 3 too many! What we need is one minimalist framework with extensibility points to allow for more advanced unit testing (say you need to run specific tests in a new app domain).

If a unit testing framework is introduced to all levels of Visual Studio, we will be doomed to at least 3 testing frameworks. One used in the SSCLI/Rotor, one used by Visual Studio (Microsoft.VisualStudio.QualityTools.UnitTestFramework) and one used by Mono and everyone else who doesn't use Visual Studio (probably NUnit)!

Testing frameworks aren't exactly rocket science. It would be possible to agree on a standard through the proper channels (i.e. the BCL/SSCLI) that everyone would use. Let's not mess it up by making 'Microsoft.VisualStudio.QualityTools.UnitTestFramework' a de facto standard!