# alibaba/PhotonLibOS

Probably the fastest coroutine lib in the world!

Repository: https://github.com/alibaba/PhotonLibOS
Canonical: https://ross.abutalabs.com/products/photonlibos
Homepage: https://PhotonLibOS.github.io
Language: C++
License: Apache-2.0
License Family: permissive
Topics: libos, iouring, net-library, fs-library, cpp, coroutine, async-io, http, rpc
Last push: 2026-09-02T03:17:21+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 86, longevity 100
- inputs: {"age_days": 1549, "days_push": 0, "days_rel": 12, "gap_med": 81, "n_releases_24m": 12}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1225, forks 178 (observed 2026-09-03T02:15:08.960844+00:00)

## What it is
PhotonLibOS is a high-performance C++ library providing a stackful coroutine runtime with a symmetric scheduler and non-blocking IO engines including io_uring. It offers networking, filesystem, HTTP, and RPC modules with POSIX-compatible APIs, and can run on a userspace TCP/IP stack over DPDK.

## Use cases
- write high-performance async C++ servers without callback hell
- convert multithreaded C++ code like RocksDB to coroutines
- build fast RPC services with zero-copy serialization
- do async file and network IO with io_uring
- run networking on a userspace TCP/IP stack with DPDK
- port async code across Linux and macOS on x86 and ARM

## When to choose
- you need maximum coroutine performance in C++ with low context-switch overhead
- you want POSIX/std-compatible APIs to integrate into legacy codebases
- you need io_uring or DPDK-backed async IO
- you want HTTP and RPC modules built into the coroutine runtime

## When to avoid
- you work in a language other than C++
- you need a full-featured application framework rather than a systems library
- your team is unfamiliar with stackful coroutines and assembly-level runtime details
- you need Windows support

## Facets
- artifact type: library
- maturity: active
- function: concurrency, http-server, rpc, serialization, file-system, networking
- domain: developer-tools, performance, microservices, backend
- platform: cpp, cross-platform
- tags: coroutine, stackful-coroutine, async-io, io-uring, libos, high-performance, dpdk, linux, macos

## Member repositories
- alibaba/PhotonLibOS (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:08.960844+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 2026-08-30T06:15:26.046988+00:00, confidence not recorded.
  - readme: https://github.com/alibaba/PhotonLibOS (fetched 2026-09-03T02:15:08.960844+00:00, sha ff3d5ed16527)
  - homepage: https://PhotonLibOS.github.io (fetched 2026-08-29T12:23:21.785850+00:00, sha 489c6ad38958)
- Data as of 2026-08-30T08:39:29.467469+00:00.