(commercial) Agilian is a complete modeling environment designed for applying agile modeling. Agilian removes the limitation of notations. Architects, project managers, analysts, designers, and developers can express their ideas freely with any notation which is suitable.
for designing for object-oriented modeling (definition of classes, relations, patterns, ...)
Art of Illusion
Art of Illusion is a free, open source 3D modelling and rendering studio. It is written entirely in Java, and should be usable on any Java Virtual Machine which is compatible with J2SE 1.4 or later. Read more
a free Java applet for embedding 3D models and panoramas in web pages without plug-ins
Java Graphical Process Designer
designs workflow/business process modelling (bpm) diagrams and exports (and imports) them, usually as XML, to workflow engines after model validation. It allows quick and easy integration of new workflow formats
a project to write an open source version of the REYES rendering algorithm used by Pixar's PhotoRealistic Renderman
written in Java + Java3d as a simple 3d editor, and as a base to build on, to try out ideas for modeling
a simple 3D sketch-based modeling and painting software. You can make rotund 3D models such as teddy bears quickly, and paint them in an integrated environment. The resulting 3D models has hierarhical joint structure, so you can use them for animation projects like Alice
Trace Modeler is an easy-to-use and smart editor for UML sequence diagrams. It can be used to document existing systems or brainstorm new designs. It instantly updates the diagram layout, freeing you to focus on the interaction content. Trace Modeler lets you be more productive and ensures your diagrams are visually pleasing and structurally correct.
Xj3D is a project of the Web3D Consortium focused on creating a toolkit for VRML97 and X3D content written completely in Java. It may be used to the import VRML content into your custom application or to create a fully-fledged browser.