As I mentioned since I released v3, I planned to release a version based on an embedded operating system. An OS will allow us to add new features easily and to port Babuino to other hardware platforms.
I started this project but I really didn't have enough time to debug the system. And it gets more difficult to debug something you are not familiar with. So I just gave up to use any available RTOS and start writing mine.
In the past 4 months I've been working on Lizard OS. It is a lightweight RTOS for small footprint microcontrollers. And the first applications running on Lizard is the Babuino v4 for Arduino. I finished this project one month ago and it is under evaluation since then.
After I finished Bv4, I started porting Lizard do the TI MSP430 Launchpad. It was not easy to make Lizard + Babuino code fit the 512B RAM in MSP430G2553 microcontroller, but I finally did it. So, Golden Lion Tamarin is the newest member of Babuino Project. I am to finish GLT software this weekend and will start some tests. I'll let you know when it's done.