By the way, while it's not a big secret that there is a big fanbase of post-apocalyptic lovers in Russia and they even made their own portal and site to support this project, a bigger surprise was that there were fans among the Unigine Corp, a Russian company that makes the game engine with the same name.
Now the thing is that as fans they decided to support the project by giving a full Unigine licence to inXile for free. Since Unigine is one of those engines that has great support for Windows, Mac OS and Linux, Brian said that it was one of the 2 engines that he is looking at. I hope Unigine gets picked, after all it utilizes DX11 technology and looks beautiful.