OmniGraffle is a diagramming application made by The Omni Group. According to the site, OmniGraffle is built specifically—and exclusively—for Mac OS X. It may be used to create diagrams of any com... More

OmniGraffle is a diagramming application made by The Omni Group. According to the site, OmniGraffle is built specifically—and exclusively—for Mac OS X. It may be used to create diagrams of any complexity, flow charts, org charts, and illustrations. 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.
In many of these respects, OmniGraffle is similar to Microsoft Visio. Indeed, the Professional version of OmniGraffle can both import and export Visio files created using Visio's XML export function. OmniGraffle 5 can also open Visio's native binary .vsd files. In recent times however OmniGraffle has undergone a phase of creeping featurism The original intuitive and powerful OmniGraffle bundled with Mac OS X Tiger, had been replaced with something so pretty much unusable.
OmniGraffle takes full advantage of Mac OS X's graphics layer, known as Quartz, and benefits from on-the-fly antialiasing, smooth scaling, transparent drop shadowing, and other features. OmniGraffle 4 added Bézier shapes and text-based hierarchical chart construction to the range of available tools. OmniGraffle 5 added Bézier connecting lines; previously connecting lines were bent to fit between their points which made them relatively easy to create, but difficult to control with any great precision.
OmniGraffle can output to PDF, TIFF, PNG, JPEG, EPS, HTML image map, SVG, Visio XML, PICT vector, Photoshop and BMP bitmap documents. It also allows intuitive mental-mapping techniques in organizing information, as well as an advanced style manager, making it very easy to lay out web page prototypes or PDF documents, as well as fast outlines or brainstorming documents. OmniGraffle uses Apple's plist XML schema to store the data. The extension is .graffle.
According to former Omni Group president Wil Shipley, Graffle "sort of stands for 'graph layout'... but in general it was a nonsense word invented just to counter 'Visio'."  [edit]  Less