# cms-sw/cmssw

CMS Offline Software

Repository: https://github.com/cms-sw/cmssw
Canonical: https://ross.abutalabs.com/products/cmssw
Homepage: http://cms-sw.github.io/
Language: C++
License: Apache-2.0
License Family: permissive
Topics: hep, cern, cms-experiment, c-plus-plus
Last push: 2026-08-26T18:43:07+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 4816, "days_push": 7, "days_rel": 7, "gap_med": 1, "n_releases_24m": 214}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1328, forks 4709 (observed 2026-08-28T04:04:23.708954+00:00)

## What it is
CMSSW is the offline software framework of the CMS experiment at CERN's Large Hadron Collider, written primarily in C++ with Python configuration. It handles event reconstruction, simulation, data processing, and physics analysis of particle collision data.

## Use cases
- reconstruct particle collision events from LHC detector data
- simulate proton-proton collisions for physics analysis
- run CMS data processing workflows on the grid
- analyze Higgs boson or standard model physics data
- build and test CMS software releases
- process detector data into physics object formats

## When to choose
- you are a CMS collaboration member analyzing or processing LHC collision data
- you need the official event reconstruction or simulation chain for the CMS detector
- you are developing or validating physics algorithms against CMS data formats

## When to avoid
- you need general-purpose particle physics simulation outside the CMS experiment
- you want a lightweight analysis tool without the CMS software ecosystem
- you are not working with CMS data formats or computing infrastructure

## Facets
- artifact type: framework
- maturity: active
- function: simulation, data-science, workflow-automation, developer-tools
- domain: data-science, simulation, developer-tools
- platform: cpp, python
- tags: high-energy-physics, cern, particle-physics, lhc, cms-experiment, detector-reconstruction, event-processing, scientific-computing, physics, linux, macos, gpu

## Member repositories
- cms-sw/cmssw (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:23.708954+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 2026-08-30T04:45:51.126824+00:00, confidence not recorded.
  - readme: https://github.com/cms-sw/cmssw (fetched 2026-08-28T04:04:23.708954+00:00, sha 8731bfa465c1)
  - homepage: http://cms-sw.github.io/ (fetched 2026-08-29T12:04:51.983684+00:00, sha dee7f03bb2cf)
- Data as of 2026-08-30T08:39:29.467469+00:00.