Meld helps you compare files, directories, and version controlled projects. It provides two- and three-way comparison of both files and directories, and has support for many popular version control systems.
Meld also works with binary files when they aren't converted to hex first. It shows hex values for things which aren't in the char set, otherwise normal chars, which is useful with binary files that also contain some ascii text. Many do, at least
Meld can compliment source code management version control systems such as Git in merging branches. The programmer can determine which changes to revert based on the line number output.