I would like to know which UML Sofware has been used to create the UML Diagram on the WordPress Developper Website : http://codex.wordpress.org/images/8/83/WP_27_dbsERD.png
Looks like some old version of MySQL Workbench to me. The new version creates more elegant pictures.
P.S. There are no actual foreign keys in WordPress, since they’re based on MyISAM tables, so I guess those lines were drawn in Paint or smth 😀
OK I should have looked a little more.
The answer is MySQL Workbench : http://dev.mysql.com/downloads/workbench/5.0.html