# hnes/libaco

A blazing fast and lightweight C asymmetric coroutine library  💎 ⛅🚀⛅🌞

Repository: https://github.com/hnes/libaco
Canonical: https://ross.abutalabs.com/products/libaco
Homepage: https://libaco.org
Language: C
License: Apache-2.0
License Family: permissive
Topics: c, coroutine, coroutine-library, high-performance, lightweight
Last push: 2022-05-21T10:53:21+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 2986, "days_push": 1565, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3695, forks 404 (observed 2026-08-28T04:08:14.855211+00:00)

## What it is
libaco is a blazing fast, lightweight C asymmetric coroutine library supporting the Sys V ABI on Intel386 and x86-64. It offers standalone or shared stack coroutines with ~10ns context switches and extreme memory efficiency (10M coroutines in ~2.8GB).

## Use cases
- run millions of lightweight coroutines in a C program
- fast cooperative multitasking with minimal context switch overhead
- share stacks across coroutines to save memory
- embed coroutines into a C server or networking application
- learn how a correct and fast coroutine library is implemented

## When to choose
- you need production-grade C coroutines on x86/x86-64 with Sys V ABI compliance
- memory efficiency and context switch speed are critical
- you want a tiny dependency-free library under 700 lines of code

## When to avoid
- you need portable coroutines beyond Intel386/x86-64 Sys V ABI
- you prefer higher-level async runtimes in languages like Go or Rust
- you need actively developed features - the project is in maintenance mode

## Facets
- artifact type: library
- maturity: maintenance
- function: concurrency
- domain: developer-tools, performance, programming-languages
- platform: cpp, c
- tags: coroutine, asymmetric-coroutine, shared-stack, high-performance, sysv-abi, lightweight, linux

## Member repositories
- hnes/libaco (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:14.855211+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 2026-08-29T18:31:05.552328+00:00, confidence not recorded.
  - readme: https://github.com/hnes/libaco (fetched 2026-08-28T04:08:14.855211+00:00, sha 4cf9eb7d3b55)
  - homepage: https://libaco.org (fetched 2026-08-29T09:24:44.295264+00:00, sha c04014fcc0b2)
- Data as of 2026-08-30T08:39:29.467469+00:00.