mrdoob/three.js

Prefer the fork only for legacy compatibility or its specific early custom features. For new work, upstream three.js is the better choice because this branch is far behind and appears abandoned.

Choose this fork only if you specifically need the QtCanvas3D/QML port and can accept a 2016-era codebase. For modern browser-based 3D work, upstream three.js is the better default because this fork is heavily stale and materially diverged.

Choose upstream unless you explicitly need this legacy snapshot. Prefer this fork only if compatibility with old code or archived assets matters more than modern features and maintenance.

Prefer this fork only if you need its specific historical snapshot or curated asset-heavy demo workflow. For most adopters, upstream three.js is the safer choice because this fork is materially older and heavily diverged.

Choose this fork if your priority is VR/WebXR feature coverage and legacy compatibility, and you can afford to manage a heavily diverged codebase. Prefer upstream if you want the latest fixes, simpler maintenance, and a lower-risk long-term dependency.