# erlyaws/yaws

Yaws webserver

Repository: https://github.com/erlyaws/yaws
Canonical: https://ross.abutalabs.com/products/yaws
Homepage: https://erlyaws.github.io
Language: Erlang
License: BSD-3-Clause
License Family: permissive
Topics: erlang
Last push: 2026-05-29T09:33:07+00:00

## Health v2 (maintenance only)
Score: 88/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 84, release rhythm 86, longevity 100
- inputs: {"age_days": 6403, "days_push": 96, "days_rel": 96, "gap_med": 0, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1312, forks 272 (observed 2026-08-28T04:04:20.282413+00:00)

## What it is
Yaws is a high-performance HTTP 1.1 webserver written entirely in Erlang, particularly well suited for dynamic-content web applications. It can operate in standalone mode as a regular webserver daemon or in embedded mode inside another Erlang application, handling each client with a lightweight Erlang process.

## Use cases
- serve dynamic web content from an Erlang application
- run a high-concurrency HTTP server on the BEAM
- embed a web server inside an existing Erlang/OTP app
- host websockets or server-sent events in Erlang
- build Erlang web apps with appmods instead of a separate app server
- self-host a lightweight webserver daemon on Linux

## When to choose
- your codebase is Erlang/OTP 25+ and you want the web layer in the same VM
- you need very high client concurrency with one process per connection
- you want an embeddable webserver for an OTP application rather than a reverse-proxied external server
- you value a mature, long-maintained Erlang-native webserver with websocket and SSE support

## When to avoid
- you need HTTP/2 or advanced proxying features found in Nginx/Caddy
- your application stack is not Erlang/Elixir-centric
- you develop or deploy primarily on Windows
- you rely on a large plugin/module ecosystem or commercial-grade support

## Facets
- artifact type: application
- maturity: stable
- function: http-server, websocket, templating
- domain: web-development, backend
- platform: bsd, self-hosted
- tags: erlang, otp, webserver, http-1-1, dynamic-content, embedded-webserver, server-sent-events, appmods, appmod, bsd-3-clause, rebar3, high-concurrency, linux, macos, web-server

## Member repositories
- erlyaws/yaws (main) score 88

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:20.282413+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 2026-08-30T04:49:04.761240+00:00, confidence not recorded.
  - readme: https://github.com/erlyaws/yaws (fetched 2026-08-28T04:04:20.282413+00:00, sha c5d6f732ccde)
  - homepage: https://erlyaws.github.io (fetched 2026-08-29T12:07:35.346342+00:00, sha 58f95f9f7c53)
- Data as of 2026-08-30T08:39:29.467469+00:00.