To contextualize StarUML's licensing, here is a comparison with popular UML tools:
Since the release of V2, StarUML has utilized a commercial licensing scheme. The current version, , follows a device-based licensing model , replacing the previous user-based model to reduce legal ambiguity. staruml license open source or proprietary
For users strictly requiring an open-source solution, the legacy of StarUML V1 survives through community-driven projects. To contextualize StarUML's licensing, here is a comparison