PRC files are also used by the Mobipockete-book-reader (here sometimes referred to as MOBI format[2]). The AZW format of Amazon's Kindle reading device is in turn a DRM-restricted form of the Mobipocket format.
On Palm OS, PRC files are used for applications, localized resources (overlays) and shared libraries.[1]
Structure of PRC file
In its essence, a PRC file is similar to a classic Mac OS application. It contains a PRC header, PRC resource headers and PRC resources.[3]
PRC Header
PRC Resource Header
PRC Resources
PRC Header
The PRC header is located at the beginning of the file and contains meta-information on the file:[3]
For every resource (specified by num_records), there is a resource header containing:[3]
name
type
notes
size
name
char
Name of the resource
4 bytes
ID
integer
ID number of the resource
2 bytes
offset
integer
Pointer to resource data
4 bytes
PRC Resources
Every application contains al least a Code #0 resource with size information and jump tables, a Code #1 resource with executable code and data resources containing pre-initialized values of global variables in compressed form.[3] Other resources that may be contained are forms, form objects, alerts and multimedia data, e. g. images and sounds.
References
12N. Rhodes, J. McKeehan. Palm OS Programming, Second Edition, O'Reilly, 2001, ISBN1-56592-856-3.