unbaked
4,525 games · 8,272 projectsupdated 2026-10-12

Code links only. Bring your own copy of the game. Rules

PCPC · 1997 · MMORPG

Ultima Online

Ultima Online (PC, 1997) has an open-source reimplementation, ClassicUO/ClassicUO, and 6 other public projects, including a matching decompilation and a decompilation.

Data checked 2026-10-12 · unbaked registry

Projects

ClassicUO
ReimplementationC#/FNA734 starspushed 2026-09-29BSD-2-Clause licenserelease 1.1.0.0

ClassicUO - an open source implementation of the Ultima Online Classic Client.

Mature client reimplementation

CrossUO
ReimplementationC++177 starspushed 2026-09-08AGPL-3.0 licenserelease 1.0.7

CrossUO - Open Source Ultima Online Client

Active open-source UO client 2026-09).

OUO
DecompC++170 starspushed 2026-09-24custom license

OUO: reverse engineering of Ultima Online: The Second Age server

Reverse engineering of the T2A-era official server (2026)

uo-client
Matching decompIDA Pro18 starspushed 2026-06-01custom licenserelease 1.1.0

Ultima Online T2A client recreated from Origin's 2.0.7 client decompilation

Ultima Online T2A client recreated from Origin's 2.0.7 client decompilation; latest release 1.1.0 (2026-05-31); repo created 2026-05-26

ServUO (C# .NET UO server emulator)general tool
ReimplementationC# .NET757 starspushed 2026-10-06GPL-2.0 licenserelease 57.4.1

An Ultima Online server emulator written in C# .NET

GitHub

ModernUOgeneral tool
ReimplementationC#/.NET362 starspushed 2026-10-11GPL-3.0 licenserelease 0.15.6.218

Highly Performant & Scalable Ultima Online Server Emulator

Active server emulators (also ServUO, RunUO)

Iris2
Reimplementation

Alternative 3D UO client for free shards, listed on Wikipedia. Status and source unknown.

What you need

You need your own copy of the game: these projects ship code only.

More on PC

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PCMindustrySource releaseAgent environment201929k2026-10-11PCosu!Source releaseReadable bytecode+1200719k2026-10-12PCCommand & Conquer Remastered CollectionSource release202021k2025-01-16PCRollerCoaster Tycoon 2ReimplementationAgent environment200216k2026-10-12PCDune 2000Reimplementation199818k2026-10-11PCAge of Empires IIReimplementation199914k2026-10-03PCCataclysm: Dark Days AheadSource release201313k2026-10-12PCCivilization VSource releaseReimplementation201011k2026-10-12

Found via en.wikipedia.org/wiki/List_of_game_engine_recrea, modernuo/ModernUO, runuo/runuo, ServUO/ServUO

GitHub data checked 2026-10-12. Notes are summaries from the research pass; the project pages are the authority.