I'm a fan of nhexl-mode in emacs. It does take a while to open large binaries (dozens of gigabytes), however I've managed to use it to do some rudimentary swapp

I'm a fan of nhexl-mode in emacs. It does take a while to open large binaries (dozens of gigabytes), however I've managed to use it to do some rudimentary swapping out of video files on a modern computer game.