Think of it as more of a text based World of Warcraft or Everquest 2. It's no coincidence that the makers of those games originally got their starts on MUDs. Runescape was originally a MUD that was converted to graphics. If you take away the graphics, MUDs tend to have more depth and a tighter community because they're smaller.
Anyway, you don't have to find anyone to play with, just login and there's usually anything from 250-400 people online at a time. Client address is www.aardwolf.com if you want to check it out.