Today's conference i've attended in the Free Software convention i mentioned yesterday has been about Coin3D. It has been given by Karin Kosina, SiM developer and FSFE member, and she's a woman, glad to have woman at that high level.
As a summary i'll tell you that the conference has been a introduction to Coin3D that is a nice set of libraries to work with 3D graphics at a higher level than using OpenGL. The results are quite fascinating as you can get quite impressive results with only a few lines of code. Furthermore the lib is completely compatible with OpenInventor 2.1 API.
As a Qt/KDE related note i'll say that they use Qt has the default gui binding library for their library, she said they also had bindings for GTK, MFC and Motif available but they were all quite dead and lower quality than the Qt one. Way to go :-)