Recently, I have been asked to evaluate a UML modeling tool, ArgoUML and below are my initial impressions on this tool:

• More standards compliant (have to be familiar with all UML terms, in order to efficiently use this application!)
• Generation of source code from the model (which is not supported in Visio)
• Supports Java, C#, C and PHP too.
• Pretty fast in execution, even though the UI is based on Java.. (may be I tried only small example!)
• Usability is okay - easy to understand the UI.
• And its FREE!

I have always dreamed of designing a complete Java application using any modeling tools and I think AgroUML will help me in realizing my dream!