JavaScript client-side editor for general diagramming & whiteboarding
an Open Source BPMN 2.0 / DMN 1.1 Modeler
show and edit eulumdat files
A free cross-platform editor for the DRAKON visual language.
UML diagram editor
A PlantUML editor written in Qt4
Cress is a comprehensive toolset for graphical service/workflow design
Jade is a cross-platform diagram editor built on the Qt framework.
Free drawing software for Windows, Mac OS X, and Linux
An Eclipse plug-in for the IBM FileNet P8 Content Engine and CMIS
Easy Video Editor - graphical interface to non-linear video editor