JetUML

What JetUML is

JetUML is a desktop UML editor for sketching software designs with a focused set of diagramming tools. It supports class, sequence, state, object, and use case diagrams. Association edges receive automatic layouts, and moving diagram nodes updates their paths. The editor checks diagrams for validity and reports problems through temporary notifications.

Diagrams can be exported as SVG, PNG, or JPEG images, or copied to the system clipboard for use in other applications. JetUML saves files as JSON in a documented open format, with a schema for each diagram type. The application runs on Windows, macOS, and Linux. It is distributed as Java archives, including an operating system independent archive that requires Java and JavaFX; a community Nix package is available for macOS and Linux.

JetUML is free and open source under the GNU General Public License version 3 or later. The project says the application collects no information and accesses the network only to open web pages through Help menu commands. Its focus on a small set of core UML features suits quick sketching, while larger diagrams can reduce performance.

Who it suits

JetUML suits people who want a free desktop tool for quickly sketching common UML diagrams across Windows, macOS, or Linux. It is also a fit for users who want diagram files in a documented JSON format or need to export images and copy diagrams to other applications.

Getting started

1. Visit the JetUML website.
2. Choose a Java archive for your platform.
3. For the OS-independent archive, install Java and JavaFX.
4. On macOS or Linux, a community Nix package is also available.

Verdict

Choose JetUML for free, focused UML sketching across Windows, macOS, and Linux, especially if JSON files and image export matter. Consider its performance limit when working with larger diagrams.