Haiku is a free open source operating system compatible with BeOS. I’d say the BeOS community is the new Amiga community: they love their platform and will endure as many difficulties as necessary as long as they are able to run BeOS/Haiku.
A few months ago, Qt4 was ported to BeOS/Haiku. That’s great news because it means we Qt4 developers can now target a new platform (did I say CMake is also available for Haiku?). Arora quickly followed.
Now, KDE 4 is also available for Haiku. Freezing cool.
By the way, OS/2 is another of those everybody-thought-they-were-dead platforms which are being infused new software thanks to ports of Qt4 (they need money to complete the port, donate!) and CMake
Please note I am not a KDE-on-Haiku or KDE-on-OS/2 developer. I know zero of Haiku/BeOS and I forgot almost all I knew of OS/2 programming.
PS: Comments here do not work due to hosting manfunction