SRB is a project mainly written in C, it's free.
SRB is a port of the MSPhere framework to msp430-gcc
SRB is a port of MSPhere compatible with msqp430-gcc. It mostly uses the same conventions as MSPhere, with the most important difference being the numbering of the ports - instead of using 0-7 for P1.0-P1.7 and 8-15 for P2 ports, it uses 1x and 2x names; for example, port nmber 14 is P1.4 and 21 is P2.1.
MSPhere uses GPL3, so I have to stick with it. A future rewrite may be LGPL-ed.
I can't assure you that any of this is even working as I've just done some refactoring, but I will be glad if you take your time to try it. I'll be happy if you provide me with some feedback or improvements.
See here