Modern industrial hallway with blue seating in Half-Life Diffusion mod

Shift-Two is an action-oriented mod for Half-Life 1 that continues the tradition of classic fan projects. Players find themselves in new locations where the focus is on action: frequent firefights and intense battles against HECU soldiers and aliens with no long breaks for rest.

They Hunger N’sane Pack - an add-on that updates the models of the They Hunger mod, offering two versions: a Simple Version with retro models and an HD model Remod Version that requires ZikShadow's Remod. Includes new animations, monster models, sounds, and music to enhance the atmosphere.

Catharsis is a short but atmospheric mod for Half-Life that tells the story of an unnamed scientist trying to escape from Black Mesa during the disaster.

GZDoom is a game engine based on Doom, created to run Doom, Heretic, Hexen, Strife and mods for them. It supports hardware 3D acceleration and OpenGL and Vulkan renderers, advanced graphics capabilities, ZScript, high frame rates, an improved sound system and extensive modding possibilities.

OpenRA is an open-source engine that recreates classic RTS games from the Command & Conquer series and Dune 2000. It rewrites the original engine from scratch, supports modern operating systems, online multiplayer, improved graphics and modifications, but requires the original game files for full functionality.