I am a big fan of alternative, lightweight operating systems. I still often get the impulse to wipe the linux and use exclusively plan9 in an old little netbook which is where I do all my programming.
The screenshot on KolibriOS actually looks very very nice. I am actually sick of the proliferation of graphic and desktop environments in linux, one more area that gives me headaches with the dependency trees, compilation times, and the endless variety in libraries and languages that all promise to aid in building a nice UI but ends up becoming cumbersome for someone who simply wants a versatile tool to get from A to B.
I've been actually planning on attacking this issue head-on in linux, which is the subject of a post I'm planning to write, eventually.