JavaScript libraries to detect browser capabilities/plug-ins

Question

I\'m trying to find a (preferably open source) JS library to determine as much information as possible about the user\'s Web browser environment. I know it\'s possible to ge

Answer 1

I maintain Common Feature Tests project, but it is merely a set of feature tests online, not a library. Feel free to use any of them on your page.

Sometimes I also use this simple test page for testing unknown environments (all tests there are really trivial one liners).