PlantUML is an open-source tool allowing users to create UML diagrams from a plain text language. Developed by Arnaud Roques
License: Open Source
PlantUML excels in creating UML diagrams through a code-based approach, making it suitable for developers and technical users. In contrast, ProcessMaker offers a more user-friendly interface with robust workflow management and automation features, making it ideal for businesses looking to streamline their processes.