AXARScan
Windows or DOS program with text extractor, bit editor, search, and multi-level undo.
Catch22 HexEdit 1.2
Cut, copy, paste, insert and delete data with no decrease in performance with larger files and unlimited multi-level undo and redo capability. For Microsoft Windows, and has maximum file size limit of 4Gb.
DataWorkshop
A multiplatform binary data editor with support for user defined structures. Requires Java. [Windows, Linux, MacOS]
febooti Hex Editor
A Hex Editor designed for integration into Windows properties pages.
Frhed
Small Windows executable that supports large file size, drag-and-drop editing, and direct editing of binary values. [Open Source]
Hack
A hex editor in which you can write REXX script to do whatever modification you want. [Public domain]
HexStar Version 2.11
A free hex editor for Windows NT and 2000 with many useful features. Able to work with extremely large files, depending on user's virtual memory.
XVI32
Windows program that includes complete online help and requires less than a megabyte of hard disk space.