Tool for EER Modeling

Question

Is there a good free conceptual modeling tool for EER modeling? It should support specialization, generalizaton, union, etc. I came across MySQL Workbench but it seemed to belong to the physical modeling stage(examples that I saw included 'VARCHAR' or 'INTEGER' specifications for attributes and it deals with tables rather than entities).

Answer 1

Open System Architect is brilliant.

SQL Power Architect .
It's community edition is free, and does a really great job helping you build your ERDs.
It works on Windows, Linux, and OSX.