PlantUML is an open-source tool allowing users to create UML diagrams from a plain text language. Developed by Arnaud Roques
License: Open Source
Diagramo is a user-friendly diagramming tool ideal for quick visualizations and collaborative work, while PlantUML is an open-source solution better suited for developers needing detailed UML diagrams and extensive customization. The two serve different audiences, with Diagramo focusing on ease of use and PlantUML prioritizing technical depth.