Let's begin with a grandiose task: to define the factors of the Universe.

Educating the 21st Century

Interactive Vim teaching tool

Squad is a web-based collaborative code editor.

SIMILE is focused on developing robust, open source tools that empower users to access, manage, visualize and reuse digital assets. Learn more about the SIMILE project.

Cappuccino is an open source framework that makes it easy to build desktop-caliber applications that run in a web browser.

Squeak is a modern, open source full-featured implementation of the powerful Smalltalk programming language and environment.

The framework for developing sophisticated web applications in Smalltalk

Lily is a browser-based visual programming environment. Programs are built

Processing is an open source programming language and environment for people who want to program images, animation, and sound. It is used by students, artists, designers, architects, researchers, and hobbyists for learning, prototyping, and production.

CodeIDE is an interesting site. If I had to describe it I would say that it's a social programming GUI

A pdf timeline chart of the various introductions of different programming languages.