Live Geometry screencast

Kirill Osenkov's pet project, Live Geometry, is a cool Silverlight application which lets you build geometric constructions and interact with them.
In his words, it's an "interactive designer for ruler-and-compass constructions".

Watch the 5 minute screencast and try the application on livegeometry.com.

Also, check out the class diagram illustrating the design (dependency tracking and change propagation, similar to a spreadsheet software and reminiscent of reactive programming).

PS: I wish more screencasts were that condensed. Video on the web is too slow ;-)

Sounds ingenius but maybe a bit complex( for me anyway!) but really wantto give it a go, seems like it could be really useful..

That was great, but veery fast :) I think you should make a separate 2 or 5 minute video for each tool that would explain in a slower fashion, what this tool can be used for. E.g. using a point and segment tool to draw a point and segment respectively is rather obvious, but using them to draw a circumcircle requires some deeper reflection :)

Very original! I think it's great.. but it would be nice if it was a little bit slower. But still very interesting and, IMO, very useful. Thanx for sharing!