A modular game engine. Sounds like a good idea. Many years ago I was involved in a project to create free 3D animation software as a sort of "digital puppetry for the masses" thing. We licensed Unreal Engine 3 (as it was at the time), and our devs had a tricky time of taking it all apart to weave in our bits and pieces. Still, at least Epic's people were brilliant to deal with, really supportive.<p>Sadly, the project was sold on after a few years. But some early user-created videos are still floating around.<p>Here's one, made by a 16-year-old, that won a competition we ran (while the software was still in beta) to create a 90-second short (he added some effects with Sony Vegas, but we later had those capabilities within our product):<p><a href="https://www.youtube.com/watch?v=KzgSdLhzX9Y" rel="nofollow">https://www.youtube.com/watch?v=KzgSdLhzX9Y</a><p>And here's another from one of our superusers, a fireman who used to make animated shorts while in the station waiting for overnight call-outs. This is him lobbying our devs for new features:<p><a href="https://www.youtube.com/watch?v=FaytpRjYMKQ" rel="nofollow">https://www.youtube.com/watch?v=FaytpRjYMKQ</a><p>Ah, such a fun project. Happy days ...