L4

I just checked L4 again, and remembered why I had a quick look at it before but left it without any further investigation. It has a fast IPC within 100-300 cycles, and "clean design". One idea I liked is a special page that maps all system calls such that you don't depend on sys-call offsets, where linker support comes in. I'm not sure how it works yet, so I'll find out. Yes, the downside of L4 is that its fully written in C++ and CORBA IDL. I'm not very inclined on IDL and CORBA, if not C++. Eric Raymonds' "The Art of UNIX Programming" adds to that of course. KDE is one project that abandoned IDL stuff due to complexity of management. I'm not sure about what went on with KDE as I really dislike it and don't care much about it.

Also I checked NYU research on OS, and a teacher there, is working on C extensions, which is what I'm more inclined to. C really lacks certain construct supports, one of which being "foreach" and you can encounter lots more issues in the linux kernel. Also various safety and cleanliness features can be added without introducing any language run-time.