# facebookarchive/rebound

A Java library that models spring dynamics and adds real world physics to your app.

Repository: https://github.com/facebookarchive/rebound
Canonical: https://ross.abutalabs.com/products/rebound
Homepage: http://facebook.github.io/rebound/
Language: Java
License: NOASSERTION
License Family: other
Archived: true
Last push: 2019-03-27T22:30:26+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": 4710, "days_push": 2716, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5386, forks 796 (observed 2026-08-28T04:09:17.163245+00:00)

## What it is
Rebound is a Java library from Facebook that models spring dynamics for creating natural, physics-based animations. It is a lightweight building block for driving UI animations like pagers, toggles, and scrollers rather than a general-purpose physics engine.

## Use cases
- add spring physics to android animations
- create natural bounce effects in ui transitions
- build springy pagers and toggles
- implement physics-based scrolling in a java app
- replace linear interpolators with realistic motion

## When to choose
- you want lightweight spring dynamics without a full physics engine
- you are building android or jvm ui animations that should feel natural
- you need a simple building block for custom animated components

## When to avoid
- you need a general-purpose physics simulation library
- you want spring animations for the web (use rebound-js instead)
- you need actively maintained software with recent releases

## Facets
- artifact type: library
- maturity: maintenance
- function: animation
- domain: mobile-development, graphics, cross-platform
- platform: jvm
- tags: spring-dynamics, physics-based-animation, facebook-archive, ui-animation, android

## Member repositories
- facebookarchive/rebound (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:17.163245+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 2026-08-29T17:58:25.154368+00:00, confidence not recorded.
  - readme: https://github.com/facebookarchive/rebound (fetched 2026-08-28T04:09:17.163245+00:00, sha ce51e100184f)
- Data as of 2026-08-30T08:39:29.467469+00:00.