Some time ago I shared a Scratch project by Greg8128. Greg designed is a C-like text language with a compiler/engine programmed using block programming (see this post). Two month later, as he wasn't that satisfied by this language, Greg has implemented a new language, Micron. Based on s-expression this time! And with communication with regular Scratch code using Scratch messages. Here are the documentation and the Scratch project. I really like this kind of weird experiments! It is really refreshing to see people playing and challenging with programming system design in such unexpected place.

It's really cool.