# wellcaffeinated/PhysicsJS

A modular, extendable, and easy-to-use physics engine for javascript

Repository: https://github.com/wellcaffeinated/PhysicsJS
Canonical: https://ross.abutalabs.com/products/physicsjs
Homepage: http://wellcaffeinated.net/PhysicsJS/
Language: JavaScript
License: MIT
License Family: permissive
Archived: true
Last push: 2019-03-26T23:43:28+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4908, "days_push": 2717, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3712, forks 406 (observed 2026-08-28T04:08:15.228652+00:00)

## What it is
PhysicsJS is a modular, extendable 2D physics engine for JavaScript that supports bodies, behaviors, and multiple renderers (canvas, PIXI, etc.). It is no longer maintained; the author recommends Matter.js as its successor.

## Use cases
- add 2d physics simulation to a web page
- simulate bouncing balls and collisions in the browser
- build an interactive physics demo or game in javascript
- render physics bodies with pixi or canvas
- create compound rigid bodies with constraints

## When to choose
- you need a lightweight modular physics engine for a legacy browser project
- you want a simple MIT-licensed 2d physics sandbox for experimentation

## When to avoid
- you need an actively maintained physics engine (use Matter.js instead)
- you need 3d physics
- you need long-term support or bug fixes

## Facets
- artifact type: library
- maturity: abandoned
- function: game-engine, simulation, graphics, animation
- domain: graphics, web-development, simulation
- platform: browser
- tags: physics-engine, 2d-physics, collision-detection, rigid-body, modular, unmaintained, game-development, nodejs, javascript

## Member repositories
- wellcaffeinated/PhysicsJS (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:15.228652+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:30:54.500970+00:00, confidence not recorded.
  - readme: https://github.com/wellcaffeinated/PhysicsJS (fetched 2026-08-28T04:08:15.228652+00:00, sha cb0072240bbe)
  - homepage: http://wellcaffeinated.net/PhysicsJS/ (fetched 2026-08-29T09:24:39.424102+00:00, sha 34d19893cc3b)
  - site_page: https://wellcaffeinated.net/PhysicsJS/installation (fetched 2026-08-29T09:24:39.433711+00:00, sha 09dc586ff195)
  - site_page: https://wellcaffeinated.net/PhysicsJS/docs (fetched 2026-08-29T09:24:39.436096+00:00, sha c76c81b4d6a9)
  - registry_npm: https://registry.npmjs.org/physicsjs (fetched 2026-08-29T09:24:39.440142+00:00, sha 44a6fa0223bb)
- Data as of 2026-08-30T08:39:29.467469+00:00.