The newly released Visual Studio 1.8 brings many improvements and new features, including Hot Exit to prevent losing any edits, Zen Mode to make focusing on code easier, new debugging features, more accessible settings, etc.
Microsoft has released version 1.3 of their cross-platform Visual Studio Code. The new version now supports tabs and many other features. Additionally, the Monaco code editor that VS Code is built upon has been extracted and is now available as a stand-alone package.
Chris Granger has open sourced the LightTable IDE with the 0.6 release. Third party plugin support was the highlight feature of the release. InfoQ talked to LightTable creator Chris Granger.
CodeMirror, an in-browser code editor, has released version 3.0, adding support for right-to-left scripts, arbitrary fonts and line heights, and inline widgets.
The embeddable open source web-based code editor ACE has reached version 1.0, coming with support for editing very large files, syntax highlighting for 45 languages, TextMate themes, Emacs and Vi key bindings, and other features.