Maybe FIVE could be something to look into? It's open source isometric rpg engine. It does not let you play fallout games at the moment (if ever -who knows ) ..but at least there is already built in support for fallout data; animations, graphics, maps etc. There are a few projects on development which are using this engine.

It's cross platform, uses oggvorbis for sound and uses SDL or OpenGL backend for rendering.

Build dependencies

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