OpenRaster

OpenRaster is a file format for layered raster images. It is designed to be an open alternative to Photoshop's PSD format, and similar formats used by graphics editors. It uses ZIP as a container format.

Identification
One of the files in the ZIP container is named "mimetype", and its contents are the ASCII string "image/openraster".

Specifications

 * Draft OpenRaster Specification

Software

 * GIMP

Sample files

 * http://gitorious.org/openraster/openraster-example-files/trees/master

Related formats

 * XML - Used by some of the internal files
 * PNG - Used by some of the internal files

Links

 * Wikipedia article
 * http://www.freedesktop.org/wiki/Specifications/OpenRaster/