OniLib is a visual editor that works on Oni's .dat files, reading the resources inside them and offering a customized interface for editing the individual types. It currently edits:
ABNA
AGQC
SNDD
IGST
as well as allowing one to edit Oni's saved game file, persist.dat (Intel format only). It runs on Intel and PPC Macs.

OniLib uses Sparkle to automatically check for and apply updates when they are released.