Reconstructed Commander Keen 1-3 Source Code

FWIW, the original bits run perfectly well on the mister ao486 core.

Wouldn't be surprised if you see some PRs from Carmack on such a project.

If you throw away the debug info, and don't use any generated introspection magic, there's nothing preserved normally. Compiled C code doesn't need to know the names after all. There are various leaks though - for example asserts and other debug macros/prints often end up revealing the names.

In Masters of Doom they are depicted as taking work computers out of the office to go work on their side project. I doubt IP would be the thing they’d stand on.

To some degree this is amusing. For a decade or so, we people would talk about the “borrowed” PCs. Now hacker forums talk about who owns the IP. In my childhood I never would have guessed this culture shift towards IP maximalism but I imagine the lesson that copyleft licenses only work in a copyright enforced environment finally took!

Id Software very much skirted the edge of legality by making Commander Keen outside of office hours while still employed by SoftDisk and using SoftDisk computers, and SoftDisk could have easily sued them if they wanted to. They managed to avoid that by striking a deal where the Id guys would continue to make games for SoftDisk while working on Keen and later Wolfenstein 3D.

There was a lot of code reuse between games. John Carmack is on record somewhere that the enemy navigation code from Doom and Quake still has its origins in some of the earliest 8-bit games he wrote in the 1980's.

I'm pretty sure that it's not exactly about the code, it's a case of having honed skills and techniques from multiple different sources - John Romero was bouncing around the industry and working on both larger and smaller productions, multiplatform ports, and different approaches to engine/content(he got his hands on both Origin's and Infocom's stuff, as well as a few other places) - the number of references he brought to the table could not be underestimated. John Carmack didn't have that same experience but would have been able to take a description from Romero of "at Origin we did it like this" and aim to make a very efficient version of it - his growth into borrowing academic research for inspiration came a little later. And there was also the early influence of Tom Hall who was older, able to communicate what he wanted as a producer and probably steered the programming team away from wrong turns a few times.

When you have the experience, you already know how long it takes to implement the majority of the game, when we're speaking of these early 2D games using bitmaps, tiles, small animations and some monospace text. The gameplay code is game-jam sized in most instances, so a majority of it was I/O code and asset pipelines. You can chart a safe course to get through one tiny project, and then another, and another, and build a best-of the routines that worked. The coding style would be assembly-like at this time even if they were using C - no deep callstacks, mostly imperative "load and store", which allows for a lower level form of reuse than is typical these days by breaking down the larger algorithm into "load", "mutate", "mutate", "mutate", "store" each as separate routines. So you end up with some tight code when you get to run it through a lot of projects. Softdisk provided the opportunity for building that and getting paid.

It's not legal unless the person had the rights to begin with. It may be legal for a clean room reimplementation, but not a decompilation project like this.

Looking through the readme, it seems this is a "matching decomp" type project which does not bundle assets (i.e. those get pulled from your local copy during the build).

I'm no lawyer, and this is no claim that it is/isn't one way or the other, but Super Mario 64 had a CC0 1.0 licensed decomp in 2019 with PC port in 2020 and Nintendo vehemently chased compiled copies of the game being shared and videos of the ports on YouTube but never went after the actual source code repo for either the decomp or port (which did not contain any of the assets). Of course there is nothing saying Nintendo can't wait 6 years and then issue action (just look how long they put up with Yuzu/Ryujinx before going after the decryption and other arguments just before the Switch 2 launched), but they were certainly aware of it when they took action against the resulting binaries/videos and didn't try to touch the code repo yet for one reason or another.

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