Tools to help reverse engineer binary file formats

Question

What tools are available to aid in decoding unknown binary data formats?

I know Hex Workshop and 010 Editor both support structures. These are okay

Answer 1

I still occasionally use an old hex editor called A.X.E., Advanced Hex Editor. It seems to have largely disappeared from the Internet now, though Google should still be able to find it for you. The last version I know of was version 3.4, but I've really only used the free-for-personal-use version 2.1.

Its most interesting feature, and the one I've had the most use for deciphering various game and graphics formats, is its graphical view mode. That basically just shows you the file with each byte turned into a color-coded pixel. And as simple as that sounds, it has made my reverse-engineering attempts a lot easier at times.

I suppose doing it by eye is quite the opposite of doing automatic analysis, though, and the graphical mode won't be much use for finding and following offsets...

The later version has some features that sound like they could fit your needs (scripts, regularity finder, grammar generator), but I have no idea how good they are.