The custom ASP.NET NUnit test runner is a simple utility to allow running your NUnit tests inside your ASP.NET application. This is used to allow testing inside an HttpContext without the hassles and pitfalls of trying to fake the context for a test.
I use this test runner on my Sitecore projects to allow unit testing inside the Sitecore application.
The Closure Library is a broad, well-tested, modular, and cross-browser JavaScript library. You can pull just what you need from a large set of reusable UI widgets and controls, and from lower-level utilities for DOM manipulation, server communication, animation, data structures, unit testing, rich-text editing, and more.