1)   Sequence Diagram Editor 1.6 Modeling tool that simplifies and speeds up the creation and maintenance of UML sequence diagrams and telecom/wrieless call flow diagrams. It automatically takes care of layout and formatting (across multiple pages if needed). 2)   EventStudio Sequence Diagram Designer 2.5 EventStudio is a CASE tool for Sequence Diagram, Call Flow, Message Sequence Chart, Use Case and Collaboration Diagram Generation. EventStudio goes beyond UML sequence diagram support and supports advanced constructs for Systems Engineering.