The source code for the popular Half-Life mod Natural Selection has been released for public use. Unknown Worlds' Hugh Jeremy says this will let fans and coders make their own variations, patch any remaining problems, or just dive into the code to learn a new trick or two.

A post on the Unknown Worlds site explains that the code isn't quite considered open source, due to some "legal hoo-ha." But, it assures the code is still available in its entirety at Github.

Natural Selection was first released in 2002, and was followed by a full-fledged sequel in 2012 from creator Charlie Cleveland's studio, Unknown Worlds. The studio is now working on its next new game, Subnautica.