On 3/19/10, Krzysztof Kosiński wrote:
This page has links to several existing canvas implementations. I have not analyzed all of them yet, but will keep you informed about any important http://live.gnome.org/ProjectRidley/CanvasOverview
What I can say about GooCanvas is that is certainly had some limitations in the past, but there is a new active developer who's been adding useful features to it (IIRC, clipping paths and text on path were added recently) and the bonus is that some of Inkscape developers here met this guy in 2007 in Montreal at LGM. He is mostly known as the guy who reverse engineered CDR files :) He needs GooCanvas for his diagramming application. So if you go GooCanvas way, you can be sure you'll have collaboration.
Alexandre