Mostly for entertainment and to see whether Robert Szeleney (one-man shop) has made much progress on it, I downloaded and installed SkyOS 5 beta 8.5 on my main
basement x86, an eMachines T2958 with add-in NVidia. I had tried 8.4 but had some issues. Fewer issues in 8.5. This is way-alternative, far left (or right, rather) of Linux.

For an early beta it's pretty slick. Looks and works a bit like BeOS, but more current and with a custom GUI dev system (SkyGI) that beats the heck out of X, IMHO. Sky
recognized most of my hardware without trouble except no sound. The partioner works, grub works (edit defaults), I could tweak settings and add users with varying rights.

This beta includes Bash, Blender, GIMP, Gaim, SkyVNC, Apache, Python, GCC 3.4, Mono stuff, Bochs, AbiWord, SkyPad, some games, benchmarking and sysadmin
tools. Most of what the home OS hacker would need to make sense of the system and maybe contribute code. Apps, that is. The OS is RZ's, but he wants others to
help with apps, drivers, whatever, as some have done.

SkyOS is not free, not open-source, and hardly mature, but I'm impressed that RS not only got this monster to dance (a la Young Frankenstein, needs some work) but
that he built it nearly from scratch, using GCC of course. If he keeps improving this, it might be worth advocating.

Meantime, it's a toy. GCC plus GTK with a custom IDE and the SkyOS API are the main attractions for a few hundred hackers of various skill levels registered as
beta testers. Native SkyGI apps, of which there are a few toys, work great. Ported apps like Firefox, Abiword, and the T-bird I'm using to write this, work mostly, but
are very slow compared to running the same apps on identical hardware in XP or SuSE 9.3 (as I have done).

Meantime, I recommend OpenSuSE or FreeBSD to anyone who seems to want to tinker beyond Windows. Those operating systems are mature and reliable.