I originally enquired about this at http://tex.stackexchange.com/q/162664 but misconstrued Bakoma-TeX as a Mathjax editor. Please advise if anyone objects to this question.

Barring Bakoma-TeX, are there any other WYSIWYG editors for MathJax?

To wit, I'm asking for a vaster WYSIWYG editor than that at Math StackExchange, with respect to Feature request - but it woudn't be a feature, it'd be a blessing - editing panel and preview side-by-side - fighting lag on large answers!. The tribulation on MathSE is that the preview panel is hidden below the input box. For desire of augmented productivity, I'm questing after a WYSIWYG editor in which I can view the preview/output on one monitor while working with the input on another monitor.

I tried those at http://tex.stackexchange.com/a/28389, but they don't seem to pertain to MathJax? For instance, if I input text without $, then writelatex.com fails to effect the output: