[nwoli]

I believe it’s open source so it’s a big shared work by many hands

[jsheard]

It is open source, but it looks like most of it was done by the main developer:

https://github.com/magcius/noclip.website/graphs/contributor...

[pfedak]

Many of the contributions are others reversing and implementing a new game on top of the existing API, so the really labor-intensive per-game work is still spread out reasonably well.

[gcr]

A lot of games use similar or derived map formats (for instance, most Valve games). There’s a fair bit of game-specific tinkering to do, but you sometimes don’t have to reverse-engineer a new binary format from scratch…