Navicat Data Modeler is a cross-platform visual database design software developed by PremiumSoft from Hong Kong in China. It comes with good usability, has practical functions such like: designs the database structure, performs a reverse or forward engineering process, imports models from the ODBC data source, generates complex SQL/DDL, and prints models. These can help user build high-quality conceptual, logical and physical data models easily and efficiently.

Gridraw is a simple but efficient UML drawer from Japan. It's based on spreadsheet and drawing implements, specially designed for software engineers, just in order to facilitate them to draw UML models/diagrams.

Dia (full name: Dia Diagram Editor) is a vector-based and Visio-like structured diagram drawing tool made by Alexander Larsson from Germany. It's lightweight, free to use and open-source, supports for Windows, Mac OS X and Linux.