# cython/cython

The most widely used Python to C compiler

Repository: https://github.com/cython/cython
Canonical: https://ross.abutalabs.com/products/cython
Homepage: https://cython.org
Language: Cython
License: Apache-2.0
License Family: permissive
Topics: python, cython, cpython, cpython-extensions, c, cpp, performance, big-data
Last push: 2026-08-27T00:10:17+00:00

## Health v2 (maintenance only)
Score: 99/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 99, longevity 100
- inputs: {"age_days": 5764, "days_push": 7, "days_rel": 11, "gap_med": 18.5, "n_releases_24m": 21}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 10833, forks 1618 (observed 2026-08-28T04:10:44.453231+00:00)

## What it is
Cython is an optimising static compiler that translates Python and the extended Cython language into C/C++ code for building fast CPython extension modules. It supports static type declarations, calling C/C++ functions directly, and wrapping external C libraries.

## Use cases
- speed up slow Python code by compiling it to C
- wrap an existing C or C++ library for use from Python
- add static type declarations to performance-critical Python functions
- work efficiently with large NumPy arrays and numerical data
- embed CPython into existing C/C++ applications
- write parallel code that releases the GIL

## When to choose
- you need orders-of-magnitude speedups for hot paths in CPython code
- you must interoperate with C/C++ libraries from Python
- you want a mature, widely used tool with broad CPython version compatibility
- you need fine-grained control over generated C code

## When to avoid
- you want a JIT with no build step (consider Numba or PyPy)
- your code is I/O-bound and not CPU-bound
- you target non-CPython runtimes exclusively
- you want full Python language compliance without limitations

## Facets
- artifact type: cli-tool
- maturity: stable
- function: compiler, programming-language, build-tool
- domain: programming-languages, compilers, performance, developer-tools
- platform: python, cpp, cross-platform
- tags: python-to-c, c-extensions, static-typing, cpython, numpy, performance-optimization, compiler

## Member repositories
- cython/cython (main) score 99

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:44.453231+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 2026-08-30T08:31:02.412518+00:00, confidence not recorded.
  - readme: https://github.com/cython/cython (fetched 2026-08-28T04:10:44.453231+00:00, sha 14f71ee13057)
  - homepage: https://cython.org (fetched 2026-08-29T08:16:33.777228+00:00, sha b95974b080e3)
  - site_page: http://docs.cython.org/src/quickstart/cythonize.html (fetched 2026-08-29T08:16:33.787757+00:00, sha 872a8eff209e)
  - site_page: https://docs.cython.org (fetched 2026-08-29T08:16:33.790489+00:00, sha 69d97fec9ea6)
- Data as of 2026-08-30T08:39:29.467469+00:00.