Open source (165)

The Clue!

Also known as Der Clou!

Adventure, 1994
Playable demo, Full version, Extra

Command & Conquer

Also known as Command & Conquer: Tiberium Dawn, C&C

Real-Time Strategy, 1995
Playable demo (installed), Playable demo, Update, Preview, Extra

Command & Conquer: Red Alert

Real-Time Strategy, 1996
Preview, Playable demo, Extra

csol

Traditional, 2017
Freeware, Freeware

Cyberdogs

Also known as Dogs

Shooter, 1994
Freeware, Patch, Update, Source code

Cylindrix

First-Person Shooter, 1996
Playable demo (installed), Full version, Source code

Dark Ages I: The Continents

Also known as DA1

Role-Playing, 1998
Freeware

Descent

Also known as Inferno, Descent 1

First-Person Shooter, 1994
Shareware (installed), Shareware, Shareware

Descent II

Also known as Descent 2

First-Person Shooter, 1995
Playable demo (installed), Playable demo, Playable demo, Preview, Extra

Digger Remastered

Arcade, 1999
Freeware, Freeware, Freeware, Extra, Source code

DOOM

Also known as Doom: Evil Unleashed

First-Person Shooter, 1993
Shareware (installed), Shareware, Shareware

DOOM II

Also known as DOOM II: Hell on Earth

First-Person Shooter, 1994

Doomdark's Revenge PC

Turn-Based Strategy, 1991
Freeware, Source code

Dr. Mind

Traditional, 2019
Freeware, Source code

Duke Nukem 3D

First-Person Shooter, 1996
Shareware (installed), Shareware, Extra

Dungeon Crawl: Stone Soup

Role-Playing, 2006
Freeware (installed), Freeware, Source code