A while ago we reported on mixed content editing in MPS, and how we have built a documentation language that can mix prose text with actual program nodes. We have now merged this code onto the master branch; it is also used in our requirements management language as well as in our code comments. To explain how it works, we have also extended the user guide. The respective part of the user guide can be downloaded separately. Note that this document is of course written with the documentation language itself, so it is able to bootstrap itself. There are still a few bugs which whitespace, line breaks and selection, but these will be fixed in due course.
All in all, this is a very significant enhancement for mbeddr — not so much in terms of coding of course, but in terms of being able to build an overall software engineering environment.