Spoiler alert! It's their in house doo-hickey with a dumb name, you can see it here: https://github.com/vigetlabs/colonel-kurtz
I feel like I'm missing something. When would this tool be used? Who is it for?
When I was at Viget, we used it to give non-technical editors the ability to assemble rich, responsive layouts within a CMS, based on a set of predefined components. It's a structured approach to building layouts on-the-fly that avoids the inevitable shitstorm caused by editors pasting random HTML into the body well of a WYSIWYG.
If I remember correctly, this page is an example of one created using Col Kurtz.
Ah ok, similar to stuff that Craft CMS does?
Or even Advanced Custom Fields in Wordpress.
Heh - I was ninja editing that, but yes!