Wow. That's the shortest trial I ever heard of. I'll have to set a day aside for trying out all its features. That said, using Sketchup wont tell me weather they use CSG or not. CSG and B-rep are two different ways of representing 3d solid data. The first uses primitive solids to construct more complex shapes, the latter uses polyhedral surfaces. Google it, it's interesting stuff. This has more to do with the internal workings of Sketchup rather than its capabilities. I was hoping someone on the SU team (Or someone who knows someone who knows someone...) would see the post and enlighten me.

I'm reasonably familiar with the ruby API and there are no functions or classes that relate to CSG. It seems pretty clear that it uses an exclusively B-rep model. So, should I take it up with wikipedia? Anyone?

I know. That doesn't mean it uses CSG. As I said, I'm pretty sure it uses B-rep structures to perform it's boolean operations. In fact I would even put money on them using large parts of the CGAL library.

I bumped into this (http://en.wikipedia.org/wiki/Constructive_solid_geometry) wikipedia article. I don't have Sketchup pro so I can't check but I can't imagine how CSG would fit into sketchup. I would've thought that Sketchup worked only with B-rep structures. Surely this article mistaken.