Many famous Symbian patches (e.g., Open4All RP , Install Server RP , Rom Patcher+ ) worked by modifying RPKG resources without permanent flashing. However, truly hardcore mods required repacking the RPKG itself.
While primarily for EKA2L1, collections of these files exist for popular Nokia devices like the N-Gage, 5320, 5800, N95, and E5 . Usage in EKA2L1 symbian rom rpkg
A utility used on jailbroken Symbian hardware to "dump" the Z drive into an RPKG file. Many famous Symbian patches (e
It is a "repackage" format used to bundle all contents of a Symbian device's Z: drive (the read-only system drive) into a single file. Many famous Symbian patches (e.g.
: A specialized utility for extracting and reverse-engineering ROM images. Symbian OS ROMs Collection (Internet Archive)