OmniGraffle (http://www.omnigroup.com/omnigraffle/) is a diagramming application made by The Omni Group (http://www.omnigroup.com/). OmniGraffle is built only for Mac OS X and iPad. It may be used to create diagrams, flow charts, org charts, illustrations, and graph database models. It features a drag-and-drop WYSIWYG interface. Stencils--groups of shapes to drag and drop--are available as extensions for OmniGraffle, and users can create their own stencils, for example, to get easy access to property graph editing requirements. In many of these respects, OmniGraffle is similar to Microsoft Visio.