This Summer Grigore Rosu and Dorel Lucanu are organizing a Summer School on Language Frameworks:

New programming languages are continuously proposed, and existing languages are continuously updated and extended to fit new requirements and paradigms. In such a dynamic field, tool supported frameworks to help the language designers develop their languages and experiment with them are crucial. The goal of this summer school is to present its participants six state-of-the art language frameworks at a relaxed rhythm, by means of tutorials, hands-on projects, and plenty of discussions, all in a picturesque place in the Carpathian Mountains.

Guido Wachsmuth and I will be presenting Spoofax. If you're into language design, you should consider attending.