jStat is a statistical library written in JavaScript that allows you to perform advanced statistical operations without the need of a dedicated statistical language (i.e. MATLAB or R).

Pure Javascript (Ca)nvas (Man)ipulation

HotQueue is a Python library that allows you to use Redis as a message queue within your Python programs.

Elycharts is a pure javascript charting library, easy to use and completely customizable.

Backbone supplies structure to JavaScript-heavy applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing application over a RESTful JSON interface.

The simplest possible mock library

"A grep program configured the way I like it."

A Bunch is a Python dictionary that provides attribute-style access (a la JavaScript objects).

Fast symmetric cryptography in Javascript

Uki is a fast and simple JavaScript user interface toolkit for desktop-like web applications.
It comes with a rich view-component library ranging from Slider to List and SplitPane.

oursql is a new set of mysql bindings for python 2.4+