wxHexEditor is a hex editor tool for HUGE files in Linux mainland. But it's good at Mac OS X too. This tool don't load whole file to your RAM. You can read/write files and devices up to some exabytes but currently tested up to 1 PetaByte. Now also has integrated Disassembler.

Version 0.22 Beta:

• Now supports many codepages/encodings, including almost all DOS, ECBDIC, Windows CPs.
• Also supports multi character codepages like Shift JIS, UTF8/16/32 and others....
• Added gksu and gksudo support for easy privilage elevations
• Added Russian translation, non-complete
• Fixed OS X binary issues that appears at old version due wx2.9
• Many bug fixes and some usage changes

Requirements

OS X 10.6 or later