# mozilla/shumway

Shumway is a Flash VM and runtime written in JavaScript

Repository: https://github.com/mozilla/shumway
Canonical: https://ross.abutalabs.com/products/shumway
Language: TypeScript
License: Apache-2.0
License Family: permissive
Archived: true
Last push: 2019-04-19T15:06:33+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 5372, "days_push": 2693, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3669, forks 393 (observed 2026-08-28T04:08:13.485921+00:00)

## What it is
Shumway is a Flash (SWF) virtual machine and runtime implemented entirely in JavaScript/TypeScript, rendering Flash content in the browser without native code. It was a Mozilla experiment exploring a web-standards-based replacement for the Flash plugin, including a Firefox extension.

## Use cases
- play flash swf files in the browser without a plugin
- render legacy flash animations using html5
- embed swf content in a web page
- run actionscript content in javascript
- replace adobe flash player with an open-source alternative

## When to choose
- you need to render legacy SWF/Flash content in a modern browser without native plugins
- you want to study or extend a JavaScript implementation of a Flash VM

## When to avoid
- you need a maintained, production-ready Flash player - the project is abandoned and development stopped years ago
- you need full compatibility with modern Flash content, since many features remain unimplemented
- you are building anything unrelated to legacy Flash content

## Facets
- artifact type: library
- maturity: abandoned
- function: interpreter, graphics, parser, animation
- domain: web-development, graphics, browser-extensions
- platform: browser
- tags: flash, swf, actionscript, html5, firefox-extension, vm, web-server, javascript

## Member repositories
- mozilla/shumway (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:13.485921+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 2026-08-29T18:31:21.172659+00:00, confidence not recorded.
  - readme: https://github.com/mozilla/shumway (fetched 2026-08-28T04:08:13.485921+00:00, sha 179b73b4373a)
- Data as of 2026-08-30T08:39:29.467469+00:00.