Open sourceGZDoomcommunity splinters after creator inserts AI-generated code

If you’ve even idly checked in on the robust world of Doom fan development in recent years, you’ve probably encountered one of the hundreds of gameplay mods, WAD files, or entire commercial games based on GZDoom. The open source Doom port—which can trace its lineage back to the original launch of ZDoom back in 1998—adds modern graphics rendering, quality-of-life additions, and incredibly deep modding features to the original Doom source code that John Carmack released in 1997.

Now, though, the community behind GZDoom is publicly fracturing, with a large contingent of developers uniting behind a new fork called UZDoom. The move is in apparent protest of the leadership of GZDoom creator and maintainer Cristoph Oelckers (aka Graf Zahl), who recently admitted to inserting untested AI-generated code into the GZDoom codebase.

“Due to some disagreements—some recent; some tolerated for close to 2 decades—with how collaboration should work, we’ve decided that the best course of action was to fork the project,” developer Nash Muhandes wrote on the DoomWorld forums Wednesday. “I don’t want to see the GZDoom legacy die, as do most all of us, hence why I think the best thing to do is to continue development through a fork, while introducing a different development model that highly favors transparent collaboration between multiple people.”

AI-way or the highway

Zahl’s project leadership has generated plenty of friction within the GZDoom development community over the years—this Reddit thread provides a brief history of some of the drama. But the inciting incident leading to this week’s UZDoom split seems to center in large part on Zahl’s open use of AI-generated code in a recent GZDoom update. While such use of AI coding tools is often hard to identify from the outside (as Zahl himself noted in a GitHub post), this particular instance was highlighted by Zahl’s own commented code snippet: “This is what ChatGPT told me for detecting dark mode on Linux.”