Watch this screencast to learn about the MPS basics. Markus Voelter and Vaclav Pech discuss the internals of a simple language extension and explore the details of the language design process.
This screen-cast is the first part of a series, which aims to gradually introduce the listeners into the fundamental principles of MPS.
You can also grab the sources used in the screencast and experiment yourself.
Note: You may also like to check out the second episode of the series.