Bless is a high quality, full featured hex editor.
It is written in mono/Gtk# and its primary platform is GNU/Linux. However it should be able to run without problems on every platform that mono and Gtk# run.
Bless currently provides the following features:
- Efficient editing of large data files and block devices.
- Multilevel undo - redo operations.
- Customizable data views.
- Fast data rendering on screen.
- Multiple tabs.
- Fast find and replace operations.
- A data conversion table.
- Advanced copy/paste capabilities.
- Highlighting of selection pattern matches in the file.
- Plugin based architecture.
- Export of data to text and html (others with plugins).
- Bitwise operations on data.
- A comprehensive user manual.
wxHexEditor is another Free Hex Editor, built because there is no good hex editor for Linux system, specially for big files.
- It uses 64 bit file descriptors (supports files or devices up to 2^64 bytes , means some exabytes but tested only 1 PetaByte file (yet). ).
- It does NOT copy whole file to your RAM. That make it FAST and can open files (which sizes are Multi Giga < Tera < Peta < Exabytes)
- Could open your devices on Linux, Windows or MacOSX.
- Memory Usage : Currently ~10 MegaBytes while opened multiple > ~8GB files.
- Could operate thru XOR encryption.
- Written with C++/wxWidgets GUI libs and can be used with other OSes such as Mac OS, Windows as native application.
- You can copy/edit your Disks, HDD Sectors with it.( Usefull for rescue files/partitions by hand. )
- You can delete/insert bytes to file, more than once, without creating temp file.
DHEX is a more than just another hex editor: It includes a diff mode, which can be used to easily and conveniently compare two binary files. Since it is based on ncurses and is themeable, it can run on any number of systems and scenarios. With its utilization of search logs, it is possible to track changes in different iterations of files easily. Wikipedia article
You can sort on Linux to find some more here:
http://en.wikipedia.org/wiki/Comparison_of_hex_editors