Indefatigable John Hansen has released a new beta version of NXC, his free C-like language for the NXT. It's 1.0.1b31, and according to the release news, it contains not only a lot of fixes, but also an enhanced parser and enhancements for safe threading.
One of the particularities of NXC is the fact that though it runs on the brick itself, you do not need a separate firmware - it uses the original LEGO NXT firmware.
There's also a new relase available of the associated IDE BrickCC that supports also NXC.
Check it out and provide feedback.