I've always liked WYSIWYM more anyways.
I only know one IDE that uses it: LyX
They coined and popularized it, because they are an editor and have to defend them not being WYSIWYG ten times a day, so they invented their own acronym.
But the concept of logical markup is much older. Latex and SGML mainly. And simplified SGML for application specific purpose like XML and docbook are very popular.
Actually, I currently spent most of my working time converting Open Office documentation to Latex, and I follow some of the principles as in the FPC documentation.
The main reason is that we have one base frameworks, and a couple of others layered on top of that, on top of which is again customer specific customization.
The number of copies of the OpenOffice manual got out of hand, and diffing openoffice was hard. So in desperation I grabbed to latex, and except for some minor problems with wrapping text around pictures, that works fine.
The Buildfaq is a lyx document btw