In my web surfing, I often come across mention of SourceForge in the Geek Community. I am wondering: what exactly is SourceForge and why is it so popular?

I back up important documents on a USB drive, and I use some online storage services (in case my computer crashes, house burns down, etc.). Is SourceForge just another online storage service, specifically for the saving of source code and/or executables? If so, I still don't understand why it is so popular. Anybody proficient enough with a computer to produce some of the offerings I have browsed there should be knowledgeable enough to post right on their own website. Why bother posting elsewhere?

What's the appeal of SourceForge?

Its a place where oensource projects can find developers, and host thier source code. If you are a small opensource project you wont have much if any cash to afford bandwidth which is why SF is good