Unity Engine:

https://store.unity.com


Game Maker Studio

https://www.udemy.com/make-a-game-and-learn-to-code-in-gamemaker-studio/?pmtag=MERCATOR1569&utm_content=_._pd_498972_._&utm_source=facebook&utm_medium=udemyads&utm_campaign=NEW-FB-DRT-Visitor-2Day-EN-ENG_._ci_._sl_ENG_._vi_._sd_._la_EN_.&utm_term=_._ag_Development-_._ci_._._pi_1340854312621296_._gi_all_._ai_18--65_._an_Development-BjNvlL_._lo_%5BAustralia,%20Canada,%20United%20States,%20United%20Kingdom%5D_._&k_clickid=c296ff7b-5821-43f8-9243-de2d9def5ade_95677778


Free CryEngine on GITHUB

http://www.tweaktown.com/news/52266/cryengine-goes-open-source-now-available-download/index.html

http://docs.cryengine.com/display/CEPROG/Getting+Started+with+git


Adding Windows Store Games to Steam:

https://brianlima.github.io/UWPHook/