What is the Closure Library?
The Closure Library is server-agnostic, and is intended for use with the Closure Compiler.
Who uses Closure Library?
Now that the Closure Library is open source, more and more developers outside Google are integrating the library in their own projects.
What can the Closure Library do for me?
If you are developing a large or growing application, you may benefit from the Closure Library's breadth. A well-tested library can insulate you from cross-browser compatibility issues and the minutiae of client-side programming, letting you focus on the fun stuff.