Visual Paradigm for UML is a user-friendly, full-featured UML modelling tool that supports full software development lifecycle - analysis, design, construction, testing and deployment. The UML modeling tool helps you build quality applications faster, better and cheaper. You can draw all types of UML diagrams, generate code from UML diagrams and vice versa, and generate documentation. The UML CASE tool also provides plenty UML resources - UML tutorials, UML projects and UML demonstrations.

Feature List:
+Full UML notation support
+CRC Card for finding objects
+Use case modeling (use case scheduling, description...)
+Business Workflow diagram
+Incremental round-trip engineering
+Code Generation - diagram to code, model to code
+Reverse engineering - code to diagram, code to model
+Instant Reverse for XML, DotNET dll/exe, C++, CORBA IDL
+Use Case Details Editor - An all-in-one environment for specifying a use case's details including general model specification and use case descriptions
+Full Screen Diagram Editing - Maximizes the diagramming area
+Sweeper - Drag to sweep shapes aside to make room for creating new shapes.
+EJB Diagram - Visualize EJB systems.
+EJB Code Generation and Deployment - Generate beans for your application development and deployment.
+Database generation - ERD to database tables
+ORM support - Generate Java objects correspond to a database
+Auto-sync between diagram and source code
+Report generator for generating PDF/HTML documentation
+Auto diagram layout - arrange shapes and connectors in diagrams
+Import/export XMI
+Import Rational Rose file
+Visio Integration - drawing UML diagrams with Visio stencils
+Export SVG, PNG, JPG
+Version control
+More...

Other UML CASE Tools / UML Plugins:
Windows Platform:
+SDE for Microsoft Visual Studio .NET

Cross-platform (Mac OS X/Windows/Linux):
+SDE for Oracle JDeveloper
+SDE for IBM WebSphere (WSAD)
+SDE for Borland JBuilder
+SDE for IntelliJ IDEA
+SDE for Eclipse
+SDE for NetBeans
+SDE for Sun ONE
+SDE for WebLogic Workshop
+More SDE...