Open Source astah Community Edition Alternatives

PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams. The generator can be run anywhere within JVM and integrated with various application such as wiki, text editor, IDE, programming language, documentation generator, and others.

Umbrello is a Unified Modelling Language (UML) modelling tool and code generator. It can create diagrams of software and other systems in the industry-standard UML format, and can also generate code from UML diagrams in a variety of programming languages.

UMLet is an open-source UML tool with a simple user interface: draw UML diagrams fast, export diagrams to eps, pdf, jpg, svg, and clipboard, share diagrams using Eclipse, and create new, custom UML elements.

Graphical modelling open source UML2 tool based on Eclipse environment.

NClass is a free tool to easily create UML class diagrams with full C# and Java language support. The user interface is designed to be simple and user-friendly for easy and fast development.

Modelio is an open source modeling tool supporting natively UML, BPMN and model exchange with XMI. It allows to draw all UML2 diagrams and specific diagrams for business process modeling. It is easy and powerful with the capacity to add new functionalities to the application.

Violet is a UML editor with these benefits: Very easy to learn and use. Draws nice-looking diagrams. Completely free. Cross-platform. Violet is intended for developers, students, teachers, and authors who need to produce simple UML diagrams quickly.

WhiteStarUML is a fork of StarUML with an intent to revive its Delphi code base by updating code to recent Delphi editions, reducing dependence on third party components and fixing bugs and adding new features.

UMLGraph allows the declarative specification and drawing of UML class and sequence diagrams. The current features are part of an ongoing effort aiming to provide support for all types UML diagrams.

TopCoder UML Tool is an easy to use, consistent modeling tool for use in Design and Development competitions. The new tool was built to model sequence, class, use case, and activity diagrams. On top of that, all those elements can have documentation easily attached to them.