# yui/yui3

A library for building richly interactive web applications.

Repository: https://github.com/yui/yui3
Canonical: https://ross.abutalabs.com/products/yui3
Homepage: http://yuilibrary.com/
Language: JavaScript
License: NOASSERTION
License Family: other
Last push: 2025-02-20T00:57:45+00:00

## Health v2 (maintenance only)
Score: 26/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 7, release rhythm 8, longevity 100
- inputs: {"age_days": 6480, "days_push": 560, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4159, forks 1269 (observed 2026-08-28T04:08:37.570355+00:00)

## What it is
YUI 3 is Yahoo's open-source JavaScript and CSS library for building richly interactive web applications, offering DOM utilities, UI widgets, event handling, and a modular architecture. The project was officially discontinued in August 2014 and receives no further bug or security fixes.

## Use cases
- build interactive web applications with dom manipulation and widgets
- maintain a legacy codebase that depends on YUI
- use drag and drop and grid layout components in older browsers
- reference a mature modular JavaScript framework from the pre-React era
- run YUI on Node.js for server-side rendering of pages

## When to choose
- you are maintaining or migrating an existing application already built on YUI
- you need to support very old browsers with a battle-tested legacy library
- you want to study a historically significant modular frontend framework

## When to avoid
- you are starting a new web project - use modern frameworks like React, Vue, or Svelte
- you need security patches or ongoing bug fixes
- you want an active community, modern tooling, or npm ecosystem integration

## Facets
- artifact type: library
- maturity: abandoned
- function: frontend-framework, ui-components, animation, state-management, templating
- domain: web-development, frontend, developer-tools
- platform: browser, cross-platform
- tags: javascript, css-framework, dom-manipulation, yahoo, unmaintained, legacy, nodejs

## Member repositories
- yui/yui3 (main) score 26

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:37.570355+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 2026-08-29T18:22:50.318180+00:00, confidence not recorded.
  - readme: https://github.com/yui/yui3 (fetched 2026-08-28T04:08:37.570355+00:00, sha 47df84c92fcc)
  - homepage: http://yuilibrary.com/ (fetched 2026-08-29T09:13:52.477874+00:00, sha 6e1eb7743e6f)
- Data as of 2026-08-30T08:39:29.467469+00:00.