I'm experimenting with different oses. I just want to learn about them and use them just for fun.
Yeah, that's fine for a lark, but there's not really much worth learning from Windows 2000. It is missing a lot of features that XP has; stuff as simple as msconfig.
Generally speaking cutting-edge stuff is better to muck around with software/OS wise (beta/alpha/nightly builds, etc) as what you learn there will be more beneficial going forward. Getting a taste of what is to come and whatnot. Cross platform too, as Disconsented suggested.