Linux Kernel

The Linux System has advantages in Stability, Speed, Graphical Interface, Software Development, Networking, Productivity, and Longevity.

Accodring to Linux About from LinuxJournal:

http://www.linuxjournal.com/xstatic/community/whatislinux

I don't think anyone here needs to hear the epic story behind Linux and how elegant, stable and secure it is nowadays. Shame it still hasn't become the majority kernel on desktop. I hope it does soon.

+ve:
Its very useful open source project. Stable, matches UNIX specs, free.

-ve (or may improve in these areas)
Device Driver API not stable. Keep changing frequently and not documented in one place.
Shift to C++ can drastically improve readability of code, highlighting the useful interfaces of subsystems etc.
Kernel code reading is becoming difficult and can benefit from C++.