The initial version of WMD was created by John Fraser from Attacklab. He released the system as open source almost a year ago. He started with a dedicated site (with some nice demos) and then transfered the project to Google code.
Stackoverflow team chose this editor for their site (and this is how I learned about it, and several thousands other people) due to it's simplicity and the approach it took as a markup editor (see next section 'How WMD differs from WYSIWYG editors').
As all new systems the WMD had some bugs in it and some missing features, which the Stackoverflow team wanted to be fixed. Sadly, John Fraser seemed to disapear from the face of the earth, and the version he released as opensource was a minified and obfuscated version of the system. The SO team did a marvelous job at de-obfuscating the system, and they released it for the public in Github.
I have started Phpancake as an excuse to learn the Zend Framwork. As an obvious choice I used WMD in my system too, Sadly to discover that during the de-obfuscation some features where removed, and the code itself is not named-spaced to my liking. (Not saying they did a bad job, just not my style). Since I am a Mootooler I decided to kill two birds with one stone. I refactored the system so it will be easy for me to implement new features (Which I all-ready did in some commercial systems I do), and while doing so, I changed it to be based on Mootools.
So, what we have now is a far from perfect system, BUT, it is a stable one and, I hope, it's architecture will allow easy bug tracing/fixing and easy additions of
b.t.w. any donations (I mean code donations and bug fixes) will be happiliy accepted.
How WMD differs from WYSIWYG editors
Quoted from the original site (John Fraser)
This is not a WYSIWYG editor. Writing HTML to look a certain way can make your text less accessible to blind people, search engines, mobile users, and feed readers. HTML describes a document's logical structure‚not its appearance. It just wasn't built for WYSIWYG.
So WMD is something new: a Wysiwym Markdown editor.
- Wysiwym stands for What You See Is What You Mean. WMD produces clean semantic HTML, leaving presentation details like fonts and colors up to style sheets. But you're not left in the dark about cosmetics; as you type, WMD's live preview shows you exactly what your text will look like after the current styles have been applied.
- Markdown is a simple markup language that's as easy to read and write as plain-text email. WMD uses Markdown as an input format, converting it into HTML behind the scenes. You can also mix raw HTML with Markdown, so the full expressiveness of HTML is always there if you need it.