Gran Turismo 4

Gran Turismo 4 (PS2, 2004) has an open-source reimplementation, Nenkai/OpenAdhoc, and 2 other public projects, including a matching decompilation and a static recompilation.

Data checked 2026-10-12 · unbaked registry

PS2Recomp

Projects

OpenAdhoc

ReimplementationGTAdhocToolchain (Adhoc script compiler); re-created compilable game…44 starspushed 2026-09-25GPL-3.0 license

Open-source re-implementation of Gran Turismo Scripts

Compilable source re-creation of the 'Adhoc' scripts that implement most GT game/menu logic (used by GT6 Spec II mod, GT4 randomizer); scope covers GT PSP, GT5, GT6, GT Sport

gt4-decomp

Matching decompSony ee-gcc 2.96 (001003-1) -O2 -G0, objdiff; CORE.GT4 NTSC-U SCUS-97…18 starspushed 2026-10-12MIT license

Matching decompilation of the Gran Turismo 4 (PS2) engine, AI-assisted. No game data included.

22,410/30,962 functions match (72.4%), 43.4% of code bytes (Oct 2026); AI-assisted

GT4Recomp (gt4-staticrecomp)

Static recompcustom C++20 R5900 AOT (no PCSX2/PS2Recomp core); SCUS_973.283 starspushed 2026-09-20no license

Learning-first WIP; disassembly milestones

What you need

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

Same toolchain

GameMethodYearStarsLast push

PSPSilent Hill: OriginsStatic recompReimplementation20078952026-10-09 PS2Dragon Ball Z: Budokai Tenkaichi 3Matching decompStatic recomp20072192026-10-12 PS2Ace Combat 5: The Unsung WarStatic recomp2004762026-10-06 PS2Shadow of the ColossusMatching decompStatic recomp+120051182026-10-02 PS2Dragon Quest VIII: Journey of the Cursed KingMatching decompAI-assisted decomp+12004492026-10-12 PS2Ridge Racer VStatic recomp2000462026-10-10 PS2Ratchet & ClankMatching decompAI-assisted decomp+32002422026-10-12 PS2.hack//InfectionMatching decompDecomp+22002362026-10-10

More on PS2

GameMethodYearStarsLast push

PS2Jak and Daxter: The Precursor LegacyDecompSource port+220013.6k2026-10-12 PS2Jak 3DecompReimplementation+120043.6k2026-10-12 PS2Jak IIDecompReimplementation+120033.6k2026-10-12 PS2Grand Theft Auto: San AndreasReimplementationAgent environment20042.6k2026-10-12 PS2Grand Theft Auto IIIReimplementationSource port+120012.2k2026-10-11 PS2Mortal Kombat: ArmageddonReimplementationAgent environment20061.6k2025-05-02 PS2SingStarReimplementation20041.3k2026-10-10 PS2Grand Theft Auto: Vice CityDecompReimplementation+220024132026-10-06

Found via decomp.dev/projects?platform=ps2

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