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.
Almost four months after the v3 branch was originally opened, the only partially backwards-compatible release provides the following new features:
- Use arbitrary fonts and line heights inside the editor
- Proper handling of right-to-left scripts (Arabic, Hebrew)
- Insert widgets inline (between lines) in the editor
- Replace arbitrary pieces of content with widgets
- Mark ranges of text as read-only or atomic (a single unit with respect to cursor motion)
- More modular event handling (.on / .off methods, rather than a single option per event)
- Improved add-on API (define new options, modularly add keymaps or line styles without trampling on other code)
- Support for multiple gutters
- Gutter no longer scrolls horizontally with the content
Additionally, CodeMirror provides staple editor features, such as:
- Autocompletion
- Search / replace
- Code folding
- Syntax highlighting
- Emacs / vim keybindings
- Theming
- Auto formatting of code
CodeMirror can be embedded in any JavaScript enabled web page, and has many real world uses. WebKit's Web Inspector editor can be replaced with CodeMirror, as an experimental feature, and is being considered to replace Firefox's source editor.
CodeMirror powers Brackets, an open source code editor focused on web development, created and maintained by Adobe. One feature, Quick Edit, allows users to open an inline editor showing the relevant CSS rules of a selected HTML tag.
Another CodeMirror powered IDE, Light Table, includes a real time debugger, showing inputs flowing through code to produce the final output. With a successfully funded Kickstarter, Light Table is planning to have an official launch by May of next year.