Ultima IV: 4 Open Source Clones Compared
u4-decompiled is a reverse-engineered decompilation of the original DOS executables, built to produce output nearly byte-identical to the originals for study purposes — its own readme states it isn't intended to compete with the existing remakes. Ultima IV Remastered instead targets the Commodore 64 specifically, requiring the original C64 disk images (with documented checksums) to build, while xu4 aims at easy play on modern Linux and Windows using the original DOS data files and notes the game is available as freeware from GOG. ScummVM, unlike the other three, is a general multi-game playback framework rather than an Ultima-specific project, and also requires the original data files.
Comparison table
Availability
- Status
- Playable
- Platforms
- Windows, Linux, OSX, PS3, PSP, Android, iOS, Wii, BeOS, Amiga, Atari
- Play in browser
- No
- Mobile
- Android, iOS
Project health
- Development status
- Active
- Last updated
- today
- Stars
- 2,811
- Contributors
- 970
- License
- GPL-3.0
Compatibility
- Requires original assets
- YesRequires original game data files from supported games to run.
Availability
- Status
- —
- Platforms
- C64
- Play in browser
- Mobile
- No
Project health
- Development status
- Halted
- Last updated
- 5y ago
- Stars
- 122
- Contributors
- 2
- License
- —
Compatibility
- Requires original assets
- YesRequires original untouched disk images of Ultima IV for C64 to build.
Availability
- Status
- Playable
- Platforms
- DOS
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Halted
- Last updated
- 3y ago
- Stars
- 81
- Contributors
- 1
- License
- —
Compatibility
- Requires original assets
- YesReverse-engineered decompilation of the original PC version executables of Ultima IV.
Availability
- Status
- Playable
- Platforms
- Linux, Windows
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Archived
- Last updated
- 1y ago
- Stars
- 72
- Contributors
- 18
- License
- GPL-3.0
Compatibility
- Requires original assets
- YesThe actual data files from Ultima 4 for DOS must be present at runtime; Ultima IV is available as freeware from gog.com.
| Title | ScummVM | Ultima IV Remastered | u4-decompiled | xu4 |
|---|---|---|---|---|
| Status | Playable | — | Playable | Playable |
| Platforms | Windows, Linux, OSX, PS3, PSP, Android, iOS, Wii, BeOS, Amiga, Atari | C64 | DOS | Linux, Windows |
| Play in browser | No | No | No | |
| Mobile | Android, iOS | No | No | No |
| Project health | ||||
| Development status | Active | Halted | Halted | Archived |
| Last updated | today | 5y ago | 3y ago | 1y ago |
| Stars | 2,811 | 122 | 81 | 72 |
| Contributors | 970 | 2 | 1 | 18 |
| License | GPL-3.0 | — | — | GPL-3.0 |
| Compatibility | ||||
| Requires original assets | YesRequires original game data files from supported games to run. | YesRequires original untouched disk images of Ultima IV for C64 to build. | YesReverse-engineered decompilation of the original PC version executables of Ultima IV. | YesThe actual data files from Ultima 4 for DOS must be present at runtime; Ultima IV is available as freeware from gog.com. |
| Preview | | | |
Frequently asked questions
Are the Ultima IV clones on this page open source?
Yes — every clone catalogued here is an open-source project. Availability, license, and development-status details for each one are listed in the comparison table above.
What license do these Ultima IV clones use?
ScummVM and xu4 (GPL-3.0).
Do I need to own the original Ultima IV to play these clones?
ScummVM, Ultima IV Remastered, u4-decompiled, and xu4 require original game assets to play.
Can I play any of these Ultima IV clones directly in a browser?
Yes — Ultima IV Remastered has a browser-playable build linked in the comparison table above, no install required.
Which Ultima IV clone is the most actively maintained?
ScummVM is currently under active development, based on recent commit activity. See the "Development status" row above for every clone's current status.
See the full write-up for each clone, or go back to Ultima IV.