wxHexEditor is an open source cross-platform disk/sector/file hex editor written in C++ with a wxWidgets-based user interface.
The project seems no longer developed since 2020. Last version, 0.24, released in December 2017, can be still downloaded from SourceForge and GitHub
010 Editor is a professional text/hex editor designed to edit any file, drive, or process on your machine. Using Binary Templates technology, 010 Editor allows a binary file to be parsed into a data structure that can be understood.
Okteta is a simple editor for the raw data of files. This type of program is also called hex editor or binary editor. The data is displayed in the traditional view with two columns: one with the numeric values and one with the assigned characters.
MadEdit is an Open-Source and Cross-Platform Text/Hex Editor written in C++ and wxWidgets.Discontinued
The project is no longer developed. Last version, 0.2.9, released in February 2009, can be still downloaded from SourceForge.
GHex - a hex editor for GNOME
GHex allows the user to load data from any file, view and edit it in either hex or ascii.
Useful for debugging problems with object code or encodings.
Also used by kids who cheat at computer games, by adding score or lives to saved games.
Hex Editor Neo is a binary files editing software utility for Windows. It's rich and handy set of features will help all software and hardware developers working with ASCII, hex, decimal, float, double and binary data.
DM Disk Editor and Data Recovery (DMDE) is a disk editor which can help you to understand NTFS. Its capable to view your hard disk sector wise, on MFT level, to disect mft attributes and to edit bytes on your hard disk.
WinHex is a hexadecimal editor capable of opening disks, sectors, files (native support for FAT, NTFS, Ext2/3, ReiserFS, Reiser4, UFS, CDFS, UDF) and physical memory (RAM). It can read, write and extract data for a further forensic analysis.