"... Be it only for import/export (from/within 3D warehouse) purpose:
http://www.sketchup.com/?section=education"
So, while students or labs need pay, teachers here can import/export.
Alice, integrated in Wonderland on top of Balloon 3D
in Croquet which goes beyond to collaboration, takes .mdl and .vrml files
in.
So, teachers can port interapplication visualisation free. Good!
(Thanks, though I am not yet, myself, a teacher in the formal sense,
teachers can help me)