Open source · SysML v2 · KerML
SysML v2 you can actually run.
Three independently built implementations of the OMG standard — a Go runtime, a Rust toolchain, and OMG's own reference build — reading and writing the same models, with an open, version-controlled store underneath to hold what they produce. No seat licenses. No vendor lock-in. Clone it, build it, run it today.
One open interchange, three implementations, a version-controlled store. Drag the boxes around — click opens the project, right-click shows its attributes. Edit the model and the engine redraws the diagram as you type.
This diagram is a SysML model. Run it or edit it in your browser on the OpenSysML engine (about 7 MB, downloaded once).
The start and each Pull out of Flexo are free choices; a seed picks each branch at random, the same way every time. Run picks a new random seed unless you set one, and shows it here so the debugger can replay that path. With no seed the debugger takes the engine's default branch.
Waiting events: empty
The engine re-reads the model as you type. Try changing a label or lang, adding a part of type Project, connecting it with another interface, or deleting a ; to see a diagnostic.
The stack
Four projects, independently maintained, built against the same open interfaces — a runtime, a toolchain, the reference implementation itself, and a model store to tie them together.
Open-MBEE / OpenSysML
OpenSysML
The runtime
A complete SysML v2 and KerML implementation in Go — language server, interactive REPL, and an execution runtime that instantiates parts, evaluates constraints, and runs action and state behavior on a clock, not just validates them. Ships with Python, Node, Java, Rust, Julia and MATLAB clients for its service, and a Go API.
Open-MBEE / sysml-toolkit
sysml-toolkit
The tool kit
A Rust workspace covering parsing, formatting, linting, JSON/CBOR interchange, constraint solving, and span-preserving model transformation, plus a language server and Python and WebAssembly bindings. Built for programmatic pipelines and CI, not just editing.
Systems-Modeling / SysML-v2-Pilot-Implementation
SysML v2 Pilot Implementation
The reference
The OMG Systems Modeling Community's own implementation — Eclipse Xtext editors, PlantUML visualization, and a Jupyter kernel. Both projects above track its grammar and standard library as their conformance baseline; this is the ground truth.
Open-MBEE / flexo-mms-*
Flexo MMS
The model store
A collection of microservices forming a version-controlled home for model data whose native form is RDF — a model is a graph other tools can query, diff, and merge, not a file they have to reparse. One SPARQL 1.1 quadstore underneath, JSON Web Tokens between services, and a SysML v2 API layer on top, so it plugs into the same open interchange the tools above already speak.
The wider ecosystem
OpenSysML isn't a single product — it's a stack plus the people, standards bodies, and growing library ecosystem around it.
Docs · CC BY 4.0
OpenSysML Wiki
Guides, decisions, and working notes for the project — the place to read up before digging into any one tool in the stack. Content is CC BY 4.0, separate from the code licenses above.
Standards body
OMG SysML
The Object Management Group's home for the SysML specification itself — the standard that every project in the stack implements.
Standards body
INCOSE
The International Council on Systems Engineering — the professional society behind much of the practice and methodology SysML v2 is built to support.
Parent community
OpenMBEE
The Open Model-Based Engineering Environment — open-source tooling for managing, integrating, and publishing systems models at scale, and the broader community OpenSysML grew out of.
Growing
Libraries built on OpenSysML
Parsers, exporters, editor integrations, and other open-source libraries built around SysML v2. Reach out through the wiki to get yours listed as this space grows.
Community
Join in
OpenSysML is community-run under OpenMBEE — code, models, docs and review are all welcome.
Licensing
- The OpenSysML stack uses a dual-license model: Apache-2.0 for code and CC BY 4.0 for wiki text, diagrams, and other written content.
- The one exception is the OMG reference implementation, which is licensed EPL-2.0 rather than Apache-2.0.
- See the stack above for the specific license per project.
- The diagram above bundles elkjs (EPL-2.0) and libavoid (LGPL-2.1-or-later); see the third-party notices.