Exiftool is a Perl library and a command-line tool that can be used for reading and writing metadata in files. In addition to exif images, Exiftool also supports many other file formats, such as video and audio files as well as Word documents. Note that Exiftool does not support writing metadata to some formats. While Exiftool can be helpful in a forensic analysis, it is not a forensic tool, nor is it an anti-forensic tool.
License
Exiftool is free and open source release under the same terms as Perl.
Supported Files
The exiftool website has a comprehensive list of the supported file types, and indicates if Exiftool supports reading, writing, and/or creating metadata for each file type. Exiftool's specialty is image file formats. It can extract exif and gps metadata and it can extract Maker Notes from several popular manufacturers.