A couple of days ago I saw a website for sharing code.
http://www.openprocessing.org/visuals/?visualID=2356 It has the application for which you were viewing the code, followed by a box with the code. My first instinct was that it should be a wiki, so it would be easy to quickly develop code. I should think the page would include links to the first-posted or latest maintainer-approved version of the app.
This would be pretty appropriate seeing as javascript is becoming so capable. Google builds lots of dynamic interactive stuff in Javascript, though they use their Google Web Toolkit. Now, the GWT compiles code into javascript from Java. It seems like it would be wise for a software wiki to support that language, and others. Maybe it could be treated like the different languages of Wikipedia, or maybe different languages could coexist.
It might also be reasonable to support straight Java, and Processing, the language used on the site tat inspired this idea.
Anyway such a site would bring open source collaboration to a new level.