"Now you should be able to select two files in a directory in Nautilus, right-click to bring up the context menu, and notice a Compare entry toward the bottom of the menu. Selecting Compare will run your preferred diff utility on these files as shown in the adjacent screenshot.
"If you have only a single file highlighted and bring up the context menu you will see "Compare later" in the context menu. Selecting that option places the path of the selected file onto a stack. The next time you select a single file you will see both "Compare later" and "Compare to '/.../first-file'" in the context menu.
"If you select two files, you will be able to compare those two like before, but also have the option to run a three-way comparison with a file from the "Compare later" stack. Although I mention a compare stack, currently gdiff-ext only lets you compare with the very last thing you added to the "Compare later" stack."
