Free UML Tool for Fast UML Diagrams
UMLet is a free, open-source UML tool with a simple user interface:
draw UML diagrams fast,
produce sequence and activity diagrams from plain text,
export diagrams to eps, pdf, jpg, svg, and clipboard,
share diagrams using Eclipse, and
create new, custom UML elements.
UMLet runs stand-alone or as Eclipse plug-in on Windows, OS X and Linux.
Also, check out our other tools, especially our new web-based UMLet, called UMLetino v13 beta.
New in version 13.1: relation roles are back; bugfixes
New in version 12.2: Improved launcher; transparency and color fixes for relations; several EPS export fixes
New in version 12.1: z-layer support; bug-fixes; improved pdf output
If you like UMLet, please vote for us at EclipsePluginCentral!
Custom Elements Tutorial
Sample UMLet diagrams