# opensim-org/opensim-core

SimTK OpenSim C++ libraries and command-line applications, and Java/Python wrapping.

Repository: https://github.com/opensim-org/opensim-core
Canonical: https://ross.abutalabs.com/products/opensim-core
Homepage: https://opensim.stanford.edu
Language: C++
License: Apache-2.0
License Family: permissive
Topics: science, simulation, biological-simulations, biomechanics, engineering, computational-science, computational-biology, musculoskeletal-models
Last push: 2026-09-02T22:20:53+00:00

## Health v2 (maintenance only)
Score: 86/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 60, longevity 100
- inputs: {"age_days": 4465, "days_push": 0, "days_rel": 55, "gap_med": 442, "n_releases_24m": 2}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1105, forks 390 (observed 2026-09-03T02:15:15.837101+00:00)

## What it is
OpenSim Core is a C++ library and set of command-line applications for building musculoskeletal models and running dynamic simulations of movement, with Java and Python bindings. It is the engine behind the OpenSim GUI and is widely used in biomechanics research for tasks like inverse kinematics and computed muscle control.

## Use cases
- simulate human walking and running with musculoskeletal models
- compute inverse kinematics from motion capture data
- run computed muscle control to estimate muscle forces
- scale generic musculoskeletal models to a subject's anthropometry
- script biomechanics analyses from Python or Matlab
- study orthopedics and rehabilitation interventions in simulation

## When to choose
- you need programmable, scriptable musculoskeletal simulation in C++, Python, or Java
- you want a mature, community-supported biomechanics engine with 15+ years of research use
- you need command-line tools for kinematics and muscle control pipelines

## When to avoid
- you need a graphical modeling interface - use the separate OpenSim GUI instead
- your domain is general rigid-body robotics or game physics rather than neuromuscular simulation

## Facets
- artifact type: library
- maturity: stable
- function: simulation, sdk, cli
- domain: simulation, bioinformatics, healthcare, robotics
- platform: windows, cpp, python, jvm, cross-platform
- tags: biomechanics, musculoskeletal-modeling, motion-capture, muscle-control, inverse-kinematics, computational-biology, linux, macos

## Member repositories
- opensim-org/opensim-core (main) score 86

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:15.837101+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 2026-08-30T06:45:43.282842+00:00, confidence not recorded.
  - readme: https://github.com/opensim-org/opensim-core (fetched 2026-09-03T02:15:15.837101+00:00, sha d7c1a4b2df64)
  - homepage: https://opensim.stanford.edu (fetched 2026-08-29T12:48:41.830457+00:00, sha 76d4beac0d39)
- Data as of 2026-08-30T08:39:29.467469+00:00.