The mbed team announced
a few days ago that their SDK
, that is, the new mbed library, is open source.
I'm sure more than a few folks had some reservations about such a previously closed system.
For me, it'll be very educational with great examples on how to implement the mbed library of which I'm quite fond on LPC. They have extensive internals documentation
posted up. I've scanned through it and I think it'll make a fascinating read.
It will likely open the door for porting to other Cortex M chips and platforms as well. Think LPC1769, STM32F4, Stellaris, etc.