Upgraded security NPC model in Half-Life with restored neural functionality

Half-Life: Gold is a mod for Half-Life that features completely remade textures, updated models, and improved NPC behavior.

Half-Life: Urbicide HD Pack - unofficial HD texture pack for Half-Life: Urbicide mod.

Triphammer is a standalone mod based on an early build of Half-Life Alpha v0.52, which was previously available only to journalists, and transformed into a fully playable game.

OpenNox is an open-source game engine that is the result of collaborative community work. Its main goal is to extend and improve the original game Nox.

ZPatch FO2 is a fan-made patch that improves the technical side of the game. It adds widescreen support, removes the FPS cap, enables borderless windowed mode, split-screen multiplayer, and much more.