Batch renaming utility Ant Renamer has a simple interface that quickly automates the tedious task of renaming multiple files, saving you from aggravating your carpal tunnel.

Unlike some of the competing software for renaming large number of files, it's interface isn't cluttered and full of options you don't understand, but what features are there are organized well and explained relatively well. This makes it possible for even users who aren't familiar with the software able to learn it relatively easily. It's also very stable, and never seems to choke on files with long filenames or paths, unlike some pieces of software made for this purpose. One of the better functions it has over some other similar alternatives is that it's able to rename folders with the same attributes and selectors as are used for files. While I wouldn't say it's the best software ever for this purpose, it certainly shines in places it's competitors don't. It includes translations to a very large number of languages as well, helping it be very accessible to anyone who's first language isn't English.