For sequence diagrams I much prefer http://www.websequencediagrams.com/ http://www.websequencediagrams.com/ Diagrammr could use some nicer looking styles. The

For sequence diagrams I much prefer http://www.websequencediagrams.com/ http://www.websequencediagrams.com/ Diagrammr could use some nicer looking styles. The different layouts and ability to reorder steps is quite nice though.