This is an autoCAD-Program. At the cost of DM 500.-- it is not quite cheap, but for sure worth all of its money. You can get a free version running in demo mode, which means once in a while little pop-up boxes will appear reminding you to get your demo registered. With the exception of these reminders there is no difference between the two versions. Just click the below URL!
www.m-cad.com/dpi/index.html
CSG is the abbreviation for Constructive Solid Geometry and describes the construction method of how to put together complex solids using primitives (sphere, cylinder, square).
Why is the CSG-Editor so unique? Everybody who works a lot with solids in autoCAD knows how much trouble it is for example to move a drilling that had already been fixed in place. The CSG-Editor has the solution. Click on the drilling, move, done. There is no simpler and quicker way than this!
The CSG-Editor can do much more than I could tell you in this short article. So it is really worth checking into it!