As far as I can tell, it's almost non-existent. I'm a developer and gamer, but not a game developer (at least not a very good one). With the rising cost of game development, it seems like it would be beneficial to everyone (publishers, developers, consumers, etc.) if the developers were making meaningful contributions to the open source community.

What got me thinking about this was Apple finally throwing their hat into the ring recently when they open sourced Swift, and Microsoft earlier this year publishing the source for .NET. Now most (if not all) of the biggest technology...