I had a linux server I setup as a project in College. Had a few mail clients in the dorms and some serious FTP traffic. The college was not amused, so I had to take it down. I kept the server up for personal use and played around with it a bit as I got my programming degree. It was fun to develop my C++ programs on. I tried KDE and Gnome, and just didn't like having to rebuild my kernel every time I wanted a new feature. However that system did stay up on a crappy 100mhz pentium for over a year.