Synalysis (http://www.synalysis.net) has released Synalyze It! Pro 1.7, an update to their hex editor for Mac OS X 10.5 and later.
Synalyze It! Pro allows users to edit and analyze binary files of any size. Featuring enhanced support for many character encodings, Synalyze It! Pro allows users to interactively define grammars for various file formats. Used as a modeling tool, Synalyze It! Pro can be useful for users to modify saved games or other unknown binary file formats and actively supports reverse engineering.
Version 1.7 contains several new features and fixes to the grammar directory and toolbar. Installed grammars are displayed now in the toolbar, results of custom elements are read-only, and the grammar window has been resized for smaller screens. The update also allows pascal strings to have size 0, includes a debugLog (“text”) method, and has addressed 10.9 related issues.
For a limited time, Synalyze It! Pro 1.7 is US$29.99 and available worldwide through the Mac App Store in the Developer Tools category and on the Synalysis website (via FastSpring). A student discount is also available.