In Mark Guzdial's book "Squeak, Object-Oriented Design with Multimedia 
Applications", there is a chapter on MAT, or "Multimedia Authoring Tool".

Some time ago, I briefly looked at MAT, but felt it was a bit immature 
for an HTML WSIWYG editor, but I thought it had promise.

Now I have difficulty finding *anything* new about MAT.

Has it just dropped by the wayside?

Nevin