I have been recently spending some time on the DSL Tools after a long time. I was pleasantly surprised by the latest bits from April CTP that ships with the Visual Studio SDK. I will playing with it for some time now. The installation was a breeze with no issues, and I have WinFX SDKs for Jan CTPs installed as well. That was good news as I have been trying to juggle a lot of technologies coming out of MS. The other thing I found was that you need to have the minimum of the VC++ language portion installed in the Visual Studio 2005 installation otherwise the DSL solution will give you a "ctc compiler" error. Other than that, everything you need to build a DSL designer, ships with the VS extension and the VSIP SDK download. I am having a lot of fun!