MediaWiki markup equivalent of WMD live-previewing editor? (not WYSIWYG)

Question

What editor like the WMD editor can be recommended, but using MediaWiki markup instead of Markdown? Our site is already using MediaWiki markup, but we want a slicker editor without changing Markup completely.

Requirements include:

• live preview of formatted text underneath the markup you're typing
• a toolbar for common formatting (bold, italic, links, bullets, numbered-list, code, etc.)
• keyboard shortcuts for each toolbar button (for example, CTRL+B for bold)
• Undo/redo via keyboard shortcuts (CTRL+Z/CTRL+Y) or toolbar buttons
• works well in the usual set of popular browsers (including Internet Explorer 6!)
• open source would be preferred

I've found a few options at WYSIWYG editor, but all of these seem to be WYSIWYG editors which is not exactly what I want since full-on WYSIWYG editors tend to be bug-prone and complicated at the markup level. Instead we want a plain-text markup editor with a client-side previewer, plus some UI niceties (toolbar, undo, keyboard shortcuts) to make editing markup easier.

Answer 1

Since the time this question was asked, a new WYSIWYG editor for MediaWiki was developed, VisualEditor. Unlike its predecessors, it is a de facto standard. Note that purely live preview for a wikitext editor would not be much simpler than this because MW wikitext can be insanely complex so a complicated parser would be needed, just like Parsoid used by VisualEditor.