gaphor/gaphor

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

2265 stars · 240 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

Gaphor is an open-source UML and SysML modeling application written in Python with GTK. It implements a fully-compliant UML 2 data model and supports SysML, RAAML, and C4 modeling, going beyond simple diagram drawing.

Use cases

• draw UML class diagrams
• create SysML block definition diagrams for systems engineering
• model software architecture with the C4 model
• document application design with diagrams
• build state machine and interaction diagrams
• model-based systems engineering (MBSE) modeling
• export diagrams for documentation

When to choose

• you need a free, open-source, cross-platform UML/SysML modeling tool
• you want a real UML 2 data model rather than just drawing shapes
• you do model-based systems engineering and need SysML or RAAML support
• you want an easy-to-use modeler that works for beginners and experts

When to avoid

• you need collaborative, cloud-based diagramming like Lucidchart or draw.io integrations
• you need round-trip code generation for a specific language out of the box
• you only need quick whiteboard-style sketches without a formal model

Facets

application · maturity active

gui documentation graphics developer-tools developer-tools desktop-applications simulation windows python cross-platform uml sysml c4-model mbse diagramming gtk raaml model-based-systems-engineering software-architecture linux macos desktop

Member repositories

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