MPS goes Beta
After years of development and various stages of public awareness, Jetbrains' Meta Programming System
has entered the beta testing phase - which means the tool is available publicly, and you can play with it and provide feedback to the Jetbrains folks.
In addition to making the tool itself available, they also worked providing help to get started: they have a really nice tutorial
as well as an extensive user's guide
and a (currently still quite empty :-)) discussion forum
So if you're into DSLs, you should really give this thing a try. It is quite different from traditional DSL tools. Although Jetbrains' approach has its own challenges, I think the tool is very promising and definitely worth a closer look.