What WYSIWYG editor does Stackoverflow use?

This is a great editor. Did you guys build it?

Duplicate.

From stackoverflow

• They use WMD and are currently deconstructing it. See github.

• It's a customized version of the WMD editor.

  EDIT: Jeff talked about their changes on the Stack Overflow blog: http://blog.stackoverflow.com/2009/01/updated-wmd-editor/.

• If I'm not mistaking by viewing page source it's using wmd-editor

• Duplicate: http://stackoverflow.com/questions/480289/using-the-stackoverflow-rich-text-system-closed