EventHelix.com develops tools for systems engineering and reverse engineering with sequence diagrams. EventStudio System Designer is a tool for modeling object and message interactions. Specify the design in a modeling language. EventStudio visualizes the design with sequence diagrams at multiple abstraction levels. Model multiple scenarios by just specifying the differences from a base scenario. VisualEther helps you visually analyze protocol signaling with sequence diagrams. Customize the protocols, messages and fields that are included in the diagram.