facebook/folly
An open-source C++ library developed and used at Facebook. observed · 2026-08-28
Health v2 · maintenance only
95/100
- Activity 99
- Release rhythm 87
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: 7
- age_days: 5206
- days_rel: 9
- days_push: 7
- n_releases_24m: 100
Adoption not part of the score
30507 stars · 5864 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded
Folly is Facebook's open-source C++20 component library containing a wide range of practical, performance-oriented building blocks used extensively at Meta. It complements std and Boost by providing components that are unavailable elsewhere or that meet stricter performance profiles at large scale.
Use cases
- high-performance C++ string and data structures
- concurrency primitives and synchronization utilities for C++
- fast serialization and memory-efficient containers
- shared foundation library for large C++ codebases
- replace Boost components with faster alternatives
When to choose
- you need battle-tested, performance-tuned C++ components at large scale
- you are building other C++ libraries or services that depend on Facebook open-source projects
- std or Boost components do not meet your performance requirements
When to avoid
- you want a small, focused dependency rather than a broad utility collection
- your project targets older C++ standards than C++20
- you need stable, long-term API guarantees for experimental folly modules
Facets
library · maturity stable
concurrency developer-tools serialization caching developer-tools performance cpp windows c++20 facebook performance core-library boost-alternative algorithms linux macos
1 source
- readme: https://github.com/facebook/folly · fetched 2026-08-28 · 3fe5cfaed2b1
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| facebook/folly | main | 95 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem