The available file formats are: OmniGraffle document — an OmniGraffle document. You can make the file read-only (not editable), and you can choose to include linked images in the file so that they show up properly on someone else's computer.
PDF vector image — Portable Document Format. This is a nice cross-platform format that has good support for both vector components and bitmaps.
TIFF bitmap image — Tagged Image File Format. This format supports transparency.
PNG bitmap image — Portable Network Graphics, a popular format for the Web. This format uses lossless compression to retain the details of an image while decreasing its file size. It supports transparency.
JPEG bitmap image — a popular compressed image format. You can lower the image quality to get a smaller file size.
EPS vector image — Encapsulated PostScript.
HTML image map — A hypertext file and a JPEG, PNG, or GIF image. URL actions in the original OmniGraffle document are coded into the image map as links so that the image can be clicked to follow them.
OmniOutliner document — Represent the diagram as a text outline, using the connection lines between shapes to create a hierarchy. This doesn't work as well for diagrams that don't have strictly tree-like structures.
Scalable Vector Graphics (SVG) drawing — An open internet standard that uses XML.
PICT vector image — A legacy Macintosh graphics format.
Adobe® Photoshop® image — File format for the popular image-editing application.
BMP bitmap image — A legacy graphics format.
Visio® XML drawing — The XML-based file format for the Microsoft® diagramming application.
Depending on the file format you choose, you have different options. Most offer an Export Area option, with which you can choose how much of the document to export. Current Selection — Only export the objects that are selected right now.
All Objects — Export all of the objects on the canvas, but not the empty areas.
Region — Specify a precise region of the canvas to export.
Current Canvas — Export the entire canvas.
Whole Document — Export everything, creating one image file for each canvas.