Similar idea we provide all the apis in various languages by default and the hosting. We actually run all the applications per user per request, and sandbox them for anything malicious.
I've run into this problem with all kind of sites. I would imagine at least one of those sites would of had a good idea in them. More recently, I've made a stock trading website. Whenever, I talk to anyone who was/is a stock trader they love the site and think its a great idea. The problem is how do I get that group of people to the site to begin with.