> Either they are using an engine that doesn't allow for other low level rendering options According to Wikipedia, the first version of Alias is from the 80s,

> Either they are using an engine that doesn't allow for other low level rendering options According to Wikipedia, the first version of Alias is from the 80s, and it initially ran only on IRIX. From that, I'd guess that it was initially written using IRIS GL, the predecessor of OpenGL. It probably doesn't have a separate "rendering engine"; IRIS GL and later OpenGL concepts and calls are probably strewn all over the code. Porting to anything else would probably be a significant effort.