Autodia is a command line Perl application that generates UML class diagrams from source code, SQL, and database connections. It supports multiple programming languages including SQL, and can output images (using GraphViz/VCG/SpringGraph), Dia XML and Umbrello XML, or custom formats using templates.
ExifTool is a platform-independent Perl library plus a command line application for reading, writing, and editing meta-information in image, audio, and video files. It supports many different types of metadata including EXIF, GPS, IPTC, XMP, JFIF, GeoTIFF, ICC Profile, Photoshop IRB, FlashPix, AFCP, and ID3, as well as the maker notes of many digital cameras.
Config::Maker takes a file with data in simple hierarchical format (similar to BIND and DHCP configuration files) and several templates, and produces the text by filling in the values. It is mainly useful for creating related configuration files. It can be used to generate firewall configuration scripts, DNS zone files, DHCP configuration files, a reference from a single file with all users and machines, etc. It's useful when you are not satisfied with keeping information synchronized in several places, but don't want something as complex as cfengine. Snippets of Perl can be used if all else fails.