搜了一下，一个也没用过。
http://www.osalt.com/visioStarUML 5.0
Available for: windows mac linux unix java
StarUML is a great open source UML application. Supporting UML 2.0 and MDA (Model Driven Architecture) StarUML let's you work with all related diagrams. Code generation can be done for Java, C++ and... Read more
Kivio 1.6.1
Available for: windows mac linux unix java
Kivio is part of the KOffice open source office suite. For flowcharting, network diagrams and all other graphing need Kivio solves them with an easy to user interface. As part of the KOffice office... Read more
ArgoUML 0.24
Available for: windows mac linux unix java
ArgoUML is a great UML (Unified Modeling Language) tool. Written in Java and using Java Web Start makes it easy to work with (install) and use on any platform. It has full support for the UML 1.4... Read more
OpenOffice Draw 3.0
Available for: windows mac linux unix java
Open Office Draw, part of the Open Office package, wasn't designed to compete with high-end graphics packages but is an easy to use, effective drawing tool that makes it simple to create flowcharts,... Read more
Dia
Available for: windows mac linux unix java
Dia is designed to be much like the commercial Windows program 'Visio'. It can be used to draw many different kinds of diagrams. It currently has special objects to help draw entity relationship... Read more
