LinkLib: Object-Oriented, UML

• www.gskinner.com/gmodeler/app/run.html - A Flash/JavaScript online UML diagrammer.
• UMLGraph - Declarative Drawing of UML Diagrams - Draws diagrams from source-like representation.
• UMLet diagrammer - Open source.
• www.horstmann.com/violet Violet UML diagrammer
• argouml.tigris.org/ Argo/UML - or see Poseidon
• www.gentleware.com Poseidon - Commercial with free personal version. Based on Argo, but seems better. WebStart.
• www.objectsbydesign.com/tools/umltools_byPrice.html/Objects By Design's UML product list
• www.cetus-links.org Cetus Links -- MASSIVE collection (18,000+) of OO links.