eGroupWare

I was looking for an free open source program that had a wiki, shared files, forums, etc. I found eGroupWare. It's a program that you can use in your web browser. It has a demo so you can try it out. It has tons of features that go beyond OnCourse, like a project manager and time sheet. There are some synchronization features with email clients and mobile devices, but be sure to check their site for compatibility.

From a first glance at what's out there, this seems pretty good. I'd like to look some more. I would also like to see what you've found/use.