MoonEdit Collaborative Editor

I need a simple collaborative editor for my fall Collaborative Writing course. I have one that works on my campus network, but I'd like one that works on the internet.

MoonEdit claims to be such an editor, but so far I have not been able to "host" a file that other people can edit with me in real time.

If anyone has better luck with MoonEdit, please let me know!

Update: I figured it out. I was using it with a virtual IP address. That's why it wouldn't work. That was at home. At school, where I have a dedicated, static IP address, it works fine.