Just to add to this conversation with a ref to you again: http://www.tersus.com/#Id=5325
AFAIU already, I'm not yet so sure the current modeling paradigm of Tersus is the best fit for the already visual character of web design. I'd imagine just a bridge to established things; a Tersus HTML component that just opens a WYSIWYG editor (webkit-based browser component, already enjoying out-of-the-box syntax-highlighting, design-mode, browser-mode, ala MS-Expression etc.), and an extendible template language that gets instantly parsed and linked into the Tersus HTML component for further processing.
I understand the resources are limited, though.
For best results, use the Firefox browser..