Gaphor is a UML and SysML modeling application written in Python. We designed it to be easy to use, while still being powerful. Gaphor implements a fully-compliant UML 2 data model, so it is much more than a picture drawing tool. You can use Gaphor to quickly visualize different aspects of a system as well as create complete, highly complex models.

Gaphor is designed around the following principles:

• Simplicity: The application should be easy to use. Only some basic knowledge of UML or SysML is required.
• Consistency: UML is a graphical modeling language, so all modeling is done in a diagram.
• Workability: The application should not bother the user every time they do something non-UML-ish.