Most successful indies worry even less about multi-platform support, and very few indie developers roll their own tech. A surprising amount of indie games start

Most successful indies worry even less about multi-platform support, and very few indie developers roll their own tech. A surprising amount of indie games start as GameMaker games requiring porting for any sort of proper commercial release. The more technically proficient indie developers hopped onto the Unity3D wagon given how that engine is general purpose enough for any type of project and had great support for indies early on. Subcontracting to a porting house is just as common if not more common for indies. If your game is successful on one platform a porting studio will be willing to work for a revenue percentage as indies are much more willing to give away significant percentages. Furthermore publishers are fairly willing to front the money for porting if you have a fully working game already designed and playable no matter what platform it was initially developed for. Indie games rarely push the computation and memory boundaries so porting isn't particularly difficult. The general case for Indie developers is develop for whatever you're most comfortable and worry about that other stuff once you actually have something worth worrying about. The cost of porting a game is pretty trivial if it's worth porting.