Address spaces based on paging rather than segments. Much clearer context switching code. File system crash recovery via logging.

And now using the HLT instruction so you don't chew CPU power unnecessarily, great for QEMU etc on laptops. I just sent you a patch.

Edit: all the user tests passed.

One thing I forgot to mention, now that the scheduler code has been changed the famous "you are not expected to understand this" comment is gone.