Doom II gameplay comparison showing ray traced lighting mod effects

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

Open-source reverse engineering of the Diablo 1 engine, allowing the original game to run on modern platforms with improvements and fixes.

Abysm 2: Infernal Contract is an adventure total conversion of Doom 2 on the GZDoom engine with RPG elements, in the spirit of Diablo, Dark Souls, and Strife. A hub world with quests, dungeons, and secrets awaits you, along with an inventory and leveling system, choice of starting class, magic, medieval weapons, and diverse enemies.

Diablo: The Hell 3 is a mod from the The Hell series for the original Diablo, created for hardcore players. The third installment expands on what was established in TH2. It fixes more bugs, adds much more content, is better balanced, and overall simply better.

USS Darkstar 25th Anniversary Patch - an addon that improves game textures, adds a loading screen, HD background and animated logo in the main menu, as well as an icon for the Steam library.