CodeMirror

CodeMirror is a JavaScript library that can be used to create a relatively pleasant editor interface for code-like content ― computer programs, HTML markup, and similar. If a mode has been written for the language you are editing, the code will be coloured, and the editor will optionally help you with indentation.

This is the project page for CodeMirror 2, the currently more actively developed, and recommended version. CodeMirror 1 is still available from here.

Supported modes:

Usage demos:

Real-world uses:

jsbin.com (JS playground)
Sage demo (math system)
sourceLair (online IDE)
Eloquent JavaScript (book)
Mergely (interactive diffing)
Paper.js (graphics scripting)
WeScheme (learning tool)
WebGL playground
ql.io (http API query helper)
Elm language examples
BlueGriffon (HTML editor)
JSHint (JS linter)
kl1p (paste service)

Getting the code

All of CodeMirror is released under a MIT-style license. To get it, you can download the latest release or the current development snapshot as zip files. To create a custom minified script file, you can use the compression API.

We use git for version control. The main repository can be fetched in this way:

git clone http://marijnhaverbeke.nl/git/codemirror2

CodeMirror can also be found on GitHub at marijnh/CodeMirror2. If you plan to hack on the code and contribute patches, the best way to do it is to create a GitHub fork, and send pull requests.

Documentation

The manual is your first stop for learning how to use this library. It starts with a quick explanation of how to use the editor, and then describes the API in detail.

For those who want to learn more about the code, there is an overview of the internals available. The source code itself is, for the most part, also well commented.

Support and bug reports

There is a Google group (a sort of mailing list/newsgroup thing) for discussion and news related to CodeMirror. When reporting a bug, read this first. If you have a github account, simply open an issue there. Otherwise, post something to the group, or e-mail me directly: Marijn Haverbeke.

Supported browsers

The following browsers are able to run CodeMirror:

Firefox 2 or higher
Chrome, any version
Safari 3 or higher
Internet Explorer 6 or higher
Opera 9 or higher (with some key-handling problems on OS X)

I am not actively testing against every new browser release, and vendors have a habit of introducing bugs all the time, so I am relying on the community to tell me when something breaks. See here for information on how to contact me.

Commercial support

CodeMirror is developed and maintained by me, Marijn Haverbeke, in my own time. If your company is getting value out of CodeMirror, please consider purchasing a support contract.

You'll be funding further work on CodeMirror.
You ensure that you get a quick response when you have a problem, even when I am otherwise busy.

CodeMirror support contracts exist in two forms—basic at €100 per month, and premium at €500 per month. Contact me for further information.

Download the latest release

Support CodeMirror

Donate (Paypal or bank)
Purchase commercial support

Releases:

27-01-2012: Version 2.21:

Added LESS, MySQL, Go, and Verilog modes.
Add smartIndent option.
Support a cursor in readOnly-mode.
Support assigning multiple styles to a token.
Use a new approach to drawing the selection.
Add scrollTo method.
Allow undo/redo events to span non-adjacent lines.
Lots and lots of bugfixes.

20-12-2011: Version 2.2:

Slightly incompatible API changes. Read this.
New approach to binding keys, support for custom bindings.
Support for overwrite (insert).
Custom-width and stylable tabs.
Moved more code into add-on scripts.
Support for sane vertical cursor movement in wrapped lines.
More reliable handling of editing marked text.
Add minimal emacs and vim bindings.
Rename coordsFromIndex to posFromIndex, add indexFromPos method.

21-11-2011: Version 2.18:

Fixes TextMarker.clear, which is broken in 2.17.

21-11-2011: Version 2.17:

Add support for line wrapping and code folding.
Add Github-style Markdown mode.
Add Monokai and Rubyblue themes.
Add setBookmark method.
Move some of the demo code into reusable components under lib/util.
Make screen-coord-finding code faster and more reliable.
Fix drag-and-drop in Firefox.
Improve support for IME.
Speed up content rendering.
Fix browser's built-in search in Webkit.
Make double- and triple-click work in IE.
Various fixes to modes.

27-10-2011: Version 2.16:

Add Perl, Rust, TiddlyWiki, and Groovy modes.
Dragging text inside the editor now moves, rather than copies.
Add a coordsFromIndex method.
API change: setValue now no longer clears history. Use clearHistory for that.
API change: markText now returns an object with clear and find methods. Marked text is now more robust when edited.
Fix editing code with tabs in Internet Explorer.

26-09-2011: Version 2.15:

Fix bug that snuck into 2.14: Clicking the character that currently has the cursor didn't re-focus the editor.

26-09-2011: Version 2.14:

Add Clojure, Pascal, NTriples, Jinja2, and Markdown modes.
Add Cobalt and Eclipse themes.
Add a fixedGutter option.
Fix bug with setValue breaking cursor movement.
Make gutter updates much more efficient.
Allow dragging of text out of the editor (on modern browsers).

23-08-2011: Version 2.13:

Add Ruby, R, CoffeeScript, and Velocity modes.
Add getGutterElement to API.
Several fixes to scrolling and positioning.
Add smartHome option.
Add an experimental pure XML mode.

25-07-2011: Version 2.12:

Add a SPARQL mode.
Fix bug with cursor jumping around in an unfocused editor in IE.
Allow key and mouse events to bubble out of the editor. Ignore widget clicks.
Solve cursor flakiness after undo/redo.
Fix block-reindent ignoring the last few lines.
Fix parsing of multi-line attrs in XML mode.
Use innerHTML for HTML-escaping.
Some fixes to indentation in C-like mode.
Shrink horiz scrollbars when long lines removed.
Fix width feedback loop bug that caused the width of an inner DIV to shrink.

04-07-2011: Version 2.11:

Add a Scheme mode.
Add a replace method to search cursors, for cursor-preserving replacements.
Make the C-like mode mode more customizeable.
Update XML mode to spot mismatched tags.
Add getStateAfter API and compareState mode API methods for finer-grained mode magic.
Add a getScrollerElement API method to manipulate the scrolling DIV.
Fix drag-and-drop for Firefox.
Add a C# configuration for the C-like mode.
Add full-screen editing and mode-changing demos.

Older releases...

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