Closure Tools : The Closure Compiler, Library, Templates, and Stylesheets help developers create powerful and efficient JavaScript.
Modest Maps | Home : Modest Maps is a small, extensible, and free library for designers and developers who want to use interactive maps in their own projects.
Woah.css : CSS Animation Library for eccentric web developers.
jQuery : The Write Less, Do More, JavaScript Library
Timeline : Beautifully crafted timelines that are easy, and intuitive to use.
A collection of command-line tools for researchers in machine learning, data mining, and related fields. All of the functionality is also provided in a clean C++ class library. Demo apps are included to show how to use the class library.