I'm sure it would run, say, Arch Linux with a basic wm like tvwm or cwm just fine. I have a pentium 4 with 512mb of ram and everything works great. Even Firefox

I'm sure it would run, say, Arch Linux with a basic wm like tvwm or cwm just fine. I have a pentium 4 with 512mb of ram and everything works great. Even Firefox is reasonably snappy. The kernel, Xorg, and wm together shouldn't use more than 50-100mb.