Play Counter Strike 1.6, with full multiplayer, in the browser

Is this legal? They want my social login for something that might be piracy?

It is not.

To clarify, this mixes proprietary code with GPL code from id software. Valve has spoken out about the engine used [1] before and has barred it from being used for mods on Steam.

[1] http://web.archive.org/web/20160701071741/http://www.moddb.c...

At Planimeter, back when we were "Team Sandbox," we ran into similar issues when attempting to publish Half-Life 2: Sandbox.[1] People can still find the source and game code on our repository listings from when we migrated off Google Code.

Valve Business Development did not give us the go-ahead.

Notably, we were the first usage of LuaJIT in the Source Engine, and we think that later GMod caught up to us. But you couldn't use native Lua modules prior to then. Only with our mod.

Half-Life: Update failed for the same reasons we did, and also our team was in our 20s when we were about ready to publish, too.

[1]: https://github.com/Planimeter

Wow! Fascinating. Source needed a open-source sandbox thing from the beginning. Can't believe things went the way it did - but it doesn't surprise me. The original HL SDK license also prohibited you from releasing anything but game-code in object form. Thank you for this effort.

Wow I remember playing around with your LOVE2D engine like ages ago. It was too complex for my usecase, but I remember it being one of the most fascinating projects on the love2d forums.

Thank you for your words. :)