GPL licensed (41)

Alex the Allegator

Also known as Alex the Allegator 1

Platform, 1999
Freeware (installed), Freeware, Source code

AllegroHack

Role-Playing, 2000
Freeware, System component

Barren Planet

Turn-Based Strategy, 2023
Freeware (installed), Freeware, Game expansion, Extra, Extra

Berušky

Also known as Berusky

Puzzle, 1999
Freeware, Source code, Game expansion, Extra, Extra

Buzz Aldrin's Race into Space

Simulation, 1993
Non-playable demo

Catacomb

Also known as Catacombs

Shooter, 1990
Freeware

The Catacomb Abyss

Also known as Catacomb Abyss 3D

First-Person Shooter, 1992
Shareware

Cylindrix

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

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

Dynamo Draughts

Traditional, 1992
Full version (installed), Full version

Emeritus Pong

Arcade, 2008
Freeware (installed), Freeware, Source code, System component, Freeware

Gladiator

Role-Playing, 1995
Shareware, Source code

Heretic

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

Heroes

Arcade, 1998
Freeware, Update