Great project! I think Espruino is in the same niche. However Espruino looks much more "user-friendly" - it has tutorials, it explains how to build an interpreter for certain developer boards, it has lots of hardware-specific modules with documented APIs and it has a shiny IDE for newbies.

Scheme could have it all, it even fits better, since it's a smaller language and presumable a faster one. However this project looks abandoned. Also, and interpreter written in assembler would be oh so hard to debug I think.

Do you know if there are other projects with alternative languages for STM MCUs except for eLua and Espruino?