25 wads
| File | Name | Author | Iwad | Demos | Length |
|---|---|---|---|---|---|
| oblivevil | Oblivious to Evil | Pseudonaut | doom | 2 | 3:26 |
| obsdm | Obsidian Deathmatch | Tempest | doom2 | 38 | 3:35 |
| obsidian | Hot Obsidian | Leon Kelz | doom2 | 1 | 3:57 |
| obtic11 | obtic11 | The Innocent Crew | doom2 | 51 | 7:20:43 |
| obzen | OBZEN | myolden | plutonia | 68 | 4:09:37 |
| occula | Occula | bemused & tourniquet | doom2 | 15 | 3:09:12 |
| ocean | ocean | Louigi Verona | doom2 | 4 | 3:31 |
| oceanbas | oceanbas | Brian Glines | doom2 | 3 | 8:09 |
| oceansde | Oceanside | Michael Jan Krizik (valkiriforce) | doom2 | 8 | 20:50 |
| octagon | octagon | Brian McKimens | doom | 2 | 7:23 |
| octo | octo | Unknown | doom | 3 | 1:02 |
| odam | odam | rf | doom | 1 | 5:46 |
| odark | odark | Varun Abhirama | doom | 3 | 10:59 |
| ode2dubzzz | Ode2dubzzz | SaladStream | doom2 | 222 | 3:53:36 |
| ode2impslayr | ode2impslayer | Various | doom2 | 137 | 4:16:56 |
| oderesuc | oderesuc | Jodwin | doom2 | 1 | 11:53 |
| odess_13 | odess_13 | Bob Evans | doom2 | 1 | 6:20 |
| odessa_1 | odessa_1 | Bob Evans | doom2 | 1 | 9:28 |
| odessa11 | odessa11 | Bob Evans | doom2 | 1 | 15:43 |
| odessa12 | odessa12 | Bob Evans | doom2 | 1 | 8:04 |
| odessa14 | odessa14 | Bob Evans | doom2 | 2 | 46:00 |
| odessa_2 | odessa_2 | Bob Evans | doom2 | 1 | 12:02 |
| odessa_3 | odessa_3 | Bob Evans | doom2 | 1 | 5:39 |
| odessa_6 | odessa_6 | Bob Evans | doom2 | 1 | 18:18 |
| odessa_7 | ODESSA 7 ("6 Keys of t... | Bob Evans | doom2 | 2 | 29:11 |