If you haven't heard of Haiku by now, it's probably for good reason: as of a year ago, the OS could barely connect to the internet, and certainly wasn't anywhere close to replacing your Linux build of choice. Luckily the open source replacement for the gone-but-not-forgotten BeOS of yore is maturing nicely, and it just had a bit of a coming out party at the Southern California Linux Expo this last weekend. There are still plenty of glitches to iron out, with applications like Firefox crashing and glitching frequently, and a shortage of hardware support, but the core elements of BeOS are there and just as lovable as ever.

For instance, that few second start time never gets old, same for that 60MB disk image, and the most excellent processor utilization.

Source- http://www.engadget.com/2008/02/12/haiku-brings-back-those-beos-glory-days/