Open sourced by Salesforce. Written in javascript (coffeescript), with focus on building an API to events and easy of adding custom behavior (in comparison to say CKEditor). Has multi-user editing support (multi-cursor).

EpicEditor is an embeddable JavaScript Markdown editor with split fullscreen editing, live previewing, automatic draft saving, offline support, and more. For developers, it offers a robust API, can be easily themed, and allows you to swap out the bundled Markdown parser with anything you throw at it.

Introducing Brackets a new open source code editor for the web. -- http://github.com/adobe/brackets

Chris Granger recently published an article on a side project he had been working on; an IDE called Light Table. Some of the nice features he demonstrates in the video below are:

• As a program gets written you see it compile live on the right, providing a kind of real-time debugging. You could see what a webpage will look like as you code it.
• Moveable code blocks; instead of having multiple tabs/windows open for each file you are working with, you can have just the functions your working with on the screen.
• When you click on a function or class name you see it's docs and params on the right.
• Documentation finder with unique features like lookup by namespace.

The article created quite a stir on places like Hacker News. Because of which Chris published a follow-up article (HN), where he noted:

• It will be open source.
• Light Table is built on top of the CodeMirror editor so those interested in contributing should help out CodeMirror.
• It will support support plugins.
• Developers like myself who use VIM would be able to use VIM's keybindings (Emacs too, etc).

Since so many people expressed interest in the project, he has decided to dedicate more of his time to getting Light Table off the ground and there is now a kickstarter for Light Table.

"A simple mission: To create an simple open-source, non-linear video editor for Linux."

One of the simplest linux video editing apps I've come across. Render time seems to be far greater than kdenlive's.

"Aptana Studio is a complete web development environment that combines powerful authoring tools with a collection of online hosting and collaboration services that help you and your team do more."