Having trustworthy file compare software is crucial if you frequently work with different versions of the same document. I can't stress enough how crucial it is to have a tool you can rely on to fairly compare files.
Anyone who wants to track changes in big volumes of data requires file comparison applications. My favorite application is UltraCompare because of how quick, easy, and user-friendly it is. Comparisons can be started quickly with its drag-and-drop capability, and it even supports comparisons from the command line. The ability to visually merge data is also immensely helpful for resolving conflicts.