Just to add to what mminer said: The free version is very capable and unless you make more than $100K dollars with it, you don't have to pay. "Unity Free, whi

Just to add to what mminer said: The free version is very capable and unless you make more than $100K dollars with it, you don't have to pay. "Unity Free, which include the free platform add-on products, may not be licensed or used by a commercial entity with annual gross revenues (based on prior fiscal year) in excess of US$100,000, or by an educational, academic, non-profit or government entity with a total annual budget for the entire entity (based on prior fiscal year) in excess of US$100,000." http://unity3d.com/company/legal/eula http://unity3d.com/company/legal/eula