@psyklax Eeesh, I don't even want to think about building software on an Atom CPU LOL!
I think a BSD should run fine on it, but mind your desktop environment usage as usually those are to blame for RAM use. Maybe something small like Fluxbox.
I've fallen in love with Cwm thanks to OpenBSD and it's available on other platforms. There's also Hikari which is based on Cwm but supports tiling.