When you first launched Minetest, didn't you think it was just Minecraft? Actually not. Although their interface, style, and gameplay are almost the same, Minetest is essentially a free, open-source and cross-platform voxel game engine (written in C++ and Lua, using the Irrlicht Engine). It was created by Perttu Ahola and first released in 2010, and is now developed by a team of volunteers, with significant contributions from the community. It's available for Linux-based systems, FreeBSD, Windows, Mac, and Android platforms, and provides an API for users to create their own games and mods written in Lua.

Counter-Strike (full name: Half-Life: Counter-Strike) is a multi-player first person shooter game series officially released by Valve Software in 1999, whose founders are Minh Le (AKA: Gooseman) and Jess Cliffe. It was originally just a game module for Half-Life, and finally became an independent game after being acquired by the developer of Half-Life - Valve. Its game development engine is from the original GoldSrc engine to now Source engine.