Here are some links you could find useful:


generateIt Sourceforge Project:
http://sourceforge.net/projects/generateit/


Apple Developer Page:
http://developer.apple.com/


Project Omega (gathering of apple amators developer):
http://www.projectomega.org/main.php?lg=en


University Claude Bernard Lyon 1 Computer Science UFR (french only):
http://www710.univ-lyon1.fr


One of the developer Website:
http://thdevita.perso.cegetel.net/


A Java based software of UML diagram editing: ArgoUML
http://argouml.tigris.org/


A software of UML diagram editing for Linux/KDE: Umbrello
http://uml.sourceforge.net/index.php


The most known and used software of UML diagram editing by IBM (Windows only): Rational Rose
http://www-306.ibm.com/software/awdtools/developer/rosexde/