For Commander Keen 1-3 I would have picked https://pckf.com/viewtopic.php?t=18248

No Ultimas? VI+Worlds, VII and VIII's got some. nuvie, exult, pentagram... There's also many UO servers and clients.

There were also some Eye of the Beholders and Might & Magics, but I believe ScummVM's absorbed them of their independence by now.

Push-Over has Domino-Chain. Flashback had Reminiscence.

ReflectionHLE covers Wolf3D/SOD faithfully. I know Wolf has a bunch of ports but they've always had license, compatibility or accuracy issues and run head-first into cruft.

Bstone reimplements Aliens of Gold from the released Planet Strike! sources.

I don't like to look for more of these because this year, it's a low hanging fruit for vibecoders to get easy clout from by telling clod to make them The Game (though most of them are Nintendo console focused as that's where all the more marketed games are and I believe Nintendo sucks so). I personally prefer the human-made clean room non-decompiled reimplementation ports which are more legally clear, so i'd take Freeablo over Devilution, OpenRW over re3, etc... Short-term slopjobs are no ideal, and decompilations with license washing are on borrowed time (and distract the momentum from clean-room efforts as there's gratification, even after the repercussions of legal action).

great list! always interesting to see these reverse engineered efforts, as well as straight remakes

leileilol wrote on 2026-09-20, 15:50:

No Ultimas? VI+Worlds, VII and VIII's got some. nuvie, exult, pentagram... There's also many UO servers and clients.

I never really played an Ultima game, although I heard about these projects. Never knew if they use any reverse-engineering or not, but I'll check this out, thanks!

There was a recent release of an Ultima IV mod/fangame called Threat of the Trinity (IIRC), which is said to be based on a modified engine -- perhaps also using reverse-engineering?

leileilol wrote on 2026-09-20, 15:50:

There were also some Eye of the Beholders and Might & Magics, but I believe ScummVM's absorbed them of their independence by now.

I gotta look into those blobbers, I only know ScummVM (supposedly) incorporates reconstructed code from Lure of the Temptress, which Revolution lost, unlike the code of Beneath a Steel Sky.

leileilol wrote on 2026-09-20, 15:50:

I don't like to look for more of these because this year, it's a low hanging fruit for vibecoders to get easy clout from by telling clod to make them The Game (though most of them are Nintendo console focused as that's where all the more marketed games are and I believe Nintendo sucks so).

That is very sadly true, I've already seen a couple of those (not much interested in console stuff but there's some for DOS, etc.).

leileilol wrote on 2026-09-20, 15:50:

I personally prefer the human-made clean room non-decompiled reimplementation ports which are more legally clear, so i'd take Freeablo over Devilution, OpenRW over re3, etc...

I would generally agree, but from my experience, a lot of these are far from recreating game mechanics 1:1. Daggerfall Unity plays nothing like vanilla Daggerfall, even though extensive analysis of the DOS binary was used to learn how this or that mechanic works. Wargus isn't Warcraft II (although it's pretty close I guess), and OpenRA is not at all any of the C&C games (but the code for those is thankfully available).

And aside from any legal concerns, I personally find it pretty impressive on its own that the code can be reconstructed from binaries this way.

Calvero wrote on 2026-09-20, 14:28:

For Commander Keen 1-3 I would have picked https://pckf.com/viewtopic.php?t=18248

BTW, I think that Omnispeak might be based on reverse-engineering as well but I'm not sure.

MrFlibble wrote on 2026-09-20, 13:20:

In the absence of source code releases for many older games, reverse-engineering and source code reconstruction appear to have a […]
Show full quote

In the absence of source code releases for many older games, reverse-engineering and source code reconstruction appear to have already proven themselves a viable method of achieving source-port accurate engine recreations for a good number of titles, increasing their chances for proper cross-platform functionality.

In the ideal case, the source code is a near-perfect recreation of the original, and a functional port based on it is available. But these are not as numerous as one would’ve wished I guess. There are also projects which are heavily based on reverse-engineering, but without an explicit goal to produce a reconstruction of the original code. And in some cases, the code is not available publicly at all for various reasons, only compiled binaries or a DLL.

I’ve been sort of keeping a list of such projects for a while, here’s what I’ve got so far (in alphabetical order) – this is likely pretty incomplete, so please don’t hesitate to fill in the gaps.

• Beyond Castle Wolfenstein
• Blood
• Bio Menace
• Chocolate Keen (Commander Keen 1-3)
• Commander Keen 4-6
• Cosmore (Cosmo’s Cosmic Adventure)
• CSBWin (Dungeon Master & Chaos Straikes Back)
• Dethrace (Carmageddon)
• Devilution (Diablo)
• Digger Remastered (Digger – original source code also available)
• dRally (Death Rally)
• Duke Nukem II
• Fallout 2
• Elite: The New Kind (Elite, BBC Micro version)
• Force Engine, The
• Jill of the Jungle
• Jumpman
• Lords of Midnight
• Magic Carpet
• Magic Carpet II
• REternal Daughter (Eternal Daughter)
• NEO-RAW (Another World)
• OpenDUNE (Dune II: The Building of A Dynasty)
• OpenFodder (Cannon Fodder)
• OpenJKDF2 (Star Wars: Dark Forces 2 – Jedi Knight)
• OpenTTD (Transport Tycoon Deluxe)
• Pango
• Raptor: Call of the Shadows (original source code also available)
• SDLPoP (Prince of Persia for DOS – original Apple II code also available)
• SkiFree
• Strife
• SuperZZT
• TRX (Tomb Raider 1-3)
• Wacky Wheels
• Ambermoon.net (based on reverse-engineering, but not a full reconstruction?)

Oh man!!! I did not know about Cosmo Cosmic Adventure cosmore!!! It will be amazing to build a new EXE with 60fps smooth scrolling

I love this game, I played it a lot as a kid, but the motherfucker is jerky as hell!

I think you can add OpenTS for Tiberian Sun.

https://github.com/OpenTS-Developers/OpenTS

https://en.wikipedia.org/wiki/List_of_game_en … ine_recreations

Open Jazz : https://github.com/AlisterT/openjazz/releases/tag/20260301

https://www.alister.eu/jazz/oj/

OpenJazz2 : https://github.com/faha223/OpenJazz2

https://www.jazz2online.com/

ReDuke, (as in the original Duke Nukum/em platform games) https://k1n9duk3.shikadi.net/reduke.html

Commander Genius (as in Commander Keen) https://clonekeenplus.sourceforge.io/index.php

Urban Assault was initially disassembled and reverse engineered into this, but then the original source code from TerraTools turned up in a bankruptcy auction lot so this was overtime augmented with that: UA_source: Mod for UrbanAssault (Replace original game engine)

WolverineDK wrote on 2026-09-23, 19:38:

https://en.wikipedia.org/wiki/List_of_game_en … ine_recreations

I'm sorry, but this list includes everything in one place, not just reverse-engineering efforts. For some reason, it even lists some legit source ports like Abuse or Doom, which are "technically" not even game engine recreations at all.

WolverineDK wrote on 2026-09-23, 19:38:

ReDuke, (as in the original Duke Nukum/em platform games) https://k1n9duk3.shikadi.net/reduke.html

AFAIK, ReDuke is very explicitly not based on reverse-engineering at all, I remember reading in the Duke4.net forums that the author created this engine only based on careful observation of how the game played in DOSBox, and never looked into disassembling the binaries. There was probably some kind of "reverse-engineering" involved in deciphering the game data formats so that the engine could use the original game data, but that's it.

MrFlibble wrote on 2026-09-20, 13:20:

Chocolate Keen (Commander Keen 1-3)

I briefly checked this out and I'm not sure if it qualifies when it still depends on the original DOS EXE. Comes off feeling like a minified emulator (like zeta for ZZT). There's a reason why there's a lot of "port" in quotation marks.

is the advent of AI assisted decompiling going to change this? it seems a very on trend thing right now, but i'm still thinking its fuzzy around definitions

no, it'll just taint the pool and be looked upon with scorn. Unmaintainable slop for "first port" clout is already a wide problem.

It's early days so there's lots of hype and excitement. But also some really cool usages of it.

One of the threads I'm following has a game dev using it to port Kenshi from its custom engine to Godot. He plans to implement co-op once the porting is complete.

Other uses that have been impressive are ports of console only games. Some of the better ones expand the settings/options in the game to toggle new features. But it otherwise feels exactly like the game from back in the day. With the option menu looking like something that could have been stock.

There is a lot of junk out there were people are "porting" things but don't actually know any of the code. But this is the worst the code writing will ever be. The models will improve at exponential rates and become more powerful. The old decompiling methods were slow manual processes. Now AI systems can keep knowledge of all of the code in mind to change things versus how a human mind is able to only look at small pieces at a time.

leileilol wrote on 2026-10-04, 14:55:

MrFlibble wrote on 2026-09-20, 13:20:

Chocolate Keen (Commander Keen 1-3)

I briefly checked this out and I'm not sure if it qualifies when it still depends on the original DOS EXE. Comes off feeling like a minified emulator (like zeta for ZZT). There's a reason why there's a lot of "port" in quotation marks.

Good catch, thanks! Off the list it goes then. I added a link to K1n9_Duk3's reconstruction instead (as suggested above by @Calvero), which is more appropriate to the topic anyway.

Ur-Quan Masters

https://en.wikipedia.org/wiki/The_Ur-Quan_Masters

Open source version of Star Control 2

MrFlibble: The Links I gave are at least not made with AI, but people worked their buttocks off, to make something that is their hard work. Since to me, every time I read about AI, then it is an almost automatic turn-off. For the last few weeks or so, there has been a load of indie retro games, that has AI been worked in, and it irks me like hell. I know for a fact, me and programming is a no-go . And cutting corners in programming is making people stupid/dumb. The hobbies I have, there I do not use AI. I go into the nitty-gritty Instead, cause then I can seriously learn from it.

orcish75 wrote on 2026-10-06, 19:54:

Open source version of Star Control 2

This is not a recreation, it's a literal source release from 2002.

WolverineDK wrote on 2026-10-06, 23:32:

MrFlibble: The Links I gave are at least not made with AI, but people worked their buttocks off, to make something that is their hard work.

I'm not sure I'm getting your point here, sorry. Are you implying that the source code recreations that I have found were created with AI-assisted methods/vibecoded? Or that the projects on that Wikipedia list are good on their own because of the virtue of not having been created with AI, even if they do not fit the criteria that I have specified?

MrFlibble: I think your threads are great 😀 I just gave a very polite rant and a middle finger to AI. Also I have more respect for the human being whom either makes an "emulation engine", as you called it, than AI. But at least some of the links in the wikipedia article has been a successful source reconstruction through de-compilation and dis-assembly(and reverse engineering ?), and NOT AI 😀 So I hope some of the links in that article are helpful , cause not all of is through source release. Look at Chocolate Strife as an example, it is based on the Chocolate Doom source, and reverse engineering of the Strife Game.

https://www.chocolate-doom.org/wiki/index.php … hocolate_Strife