FileCarver

FileCarver is a powerful developer tool for editing structured binary files. FileCarver increases productivity by allowing the developer to write simple XML file format definitions to quickly prototype and implement GUI editors for binary files.
Each XML file format definition describes the structure of a particular file format, which FileCarver then uses to automatically build a rich, graphical user interface for opening, viewing, editing, saving, and creating new files in that format. Editing binary files has never been this easy.
Whether you're adding binary file support into your new or existing application, and don't want to waste your time building a custom editor or viewer for its data files, or if you are required to deal with legacy file formats, FileCarver has you covered.
FileCarver is a superior solution compared to the traditional ways of editing binary files, such as creating custom programs, or using a hex editor. While custom programs allow you to create rich user interfaces to edit binary files, just as FileCarver does, they require many man-hours of development time - efforts that could be better spent elsewhere. With FileCarver, the time to implement a fully fledged editor for a binary format is reduced significantly, as the developer only needs to write an XML file format definition.
If, on the other hand, you use a hex editor to edit your binary files, you have zero development time overhead. However, using a hex editor is extremely tedious to edit anything but the simplest file formats. With a hex editor, you must manually calculate the exact offset of the data you want to edit, as well as the format of the data you are changing. While this may be adequate for very light-use of editing binary files, it does not compare to FileCarver's ability to provide you with a complete, rich user interface - indistinguishable from a custom made program - to edit the binary file.