"You can use the NS source code to make your own version of the original game, fix problems with it, make new problems, or just see how the game worked," Jeremy wrote. "We hope you enjoy tinkering with it. NS was one of the greatest mods of all time — and we can't wait to see what you are able to do with it."
He goes on to note that the code is not open source due to legal restrictions. Full details about the Natural Selection and Half Life SDK licenses are available on Natural Selection's GitHub page. The first-person RTS was first publicly released in 2002 and you can view a recent version of Natural Selection, v3.0, in action below. The mod's sequel, Natural Selection 2, launched in 2012.
The studio announced last December that it is developing an open-world underwater exploration game called Subnautica. The game will combine role playing, sandbox, exploration and cinematic games, where players will be able to build submarines and develop equipment to explore the ocean.