..none of listed renderers are multiplatform except C4 while C4 has no physics included(maybe its changed, i havent check long time)....Torque is 'multiplatform' but you have to pay for it and Im quite sure it will not be easy to make it work as you expecting since Torque itself is torture to work with..and on the top of this story as i said, all of them are graphics engines, not exactly game engines...so, if you trying to compare all of them with flexibility of Unity and its multiplatform nature..you wrong already..I have it all, except Truevision, so,I cant see easy of use with it as I see in Unity...and again as a nice multiplatform solution, none of them can match Unity..