ER/Builder Data Modeler is free for students and non-profit organisations. It allows developers to design or modify databases and supports creating entity relationship diagrams.
Supported databases: Oracle, MS SQL Server, PostgreSQL, MySQL, SQLite and Firebird.
Ranked in these QuestionsQuestion Ranking
Pro Ease of use
Only 8 Mb install size.
Pro Supports many databases
Pro ER Builder is aasy to use and a complete modeling tool
Very interesting tool, powerful and easy to use. Can do reverse and forward engineering, generate SQL script, and more.
Pro Not limited
The free version does not seem limited (for personal use).