I don't know, Fons.
There's an entire "modular DAW" called ayyi that is a fork of ardour's codebase. The author has never spoken to me once (at least not with an acknowledgement of what s/he was up to). Whoever is doing is is still active (recent releases on September 2nd). They distribute the ardour libraries as part of their source tree. They clearly want to produce something that operates in the same space as Ardour, although they have changed the name and have a very different architectural concept in mind (which over time seems to be converging back towards Ardour's own ... quelle surprise!)
I'm not wild about it, but it is also somewhat in line with my original goals when I started writing Ardour - nobody in the open source world knew how to write a DAW (*) and an example would be handy.