Hex Fiend

Hex Fiend is a fast, clever, and free Hex Editor that has many unique features:
- Insert, delete, rearrange: Hex Fiend does not limit you to in-place changes like some hex editors.
- Work with huge files: Hex Fiend can handle as big a file as you're able to create.

It's been tested on files as large as 118 GB.
- Small footprint: Hex Fiend does not keep your files in memory. You won't dread launching or working with Hex Fiend even on low-RAM machines.
- Fast: Open a huge file, scroll around, copy and paste, all instantly. Find what you're looking for with fast searching.
- Binary diff: Hex Fiend can show the differences between files, taking into account insertions or deletions.
- Smart saving: Hex Fiend knows not to waste time overwriting the parts of your files that haven't changed, and never needs temporary disk space.
- Data inspector: Interpret data as integer or floating point, signed or unsigned, big or little endian...
- Embeddable: It's really easy to incorporate Hex Fiend's hex or data views into your app. Its permissive BSD-style license won't burden you.