magicfilter is an extensible and customizable automatic printer filter. It selects an appropriate conversion technique for the input data by seeking for magic numbers, and then utilizing the appropriate conversion utility. It is primarily intended for use as the "input filter" by the lpd print spooler. The options accepted by magicfilter are exactly the ones passed to the input filter by lpd.
CUPS is a wonderful printing system that uses the emerging IPP protocol. The only drawback is that there is quite no free driver available to print with. CUPS-drivers address this issue by providing a generic printer driver using GNU GhostScript. Not many printers are supported to date, but all is in place to support as many printers as GS can. If GS supports your printer, then CUPS-drivers will support it as well. Help and feedback are welcomed.
The t1utils package contains six programs that manipulate PostScript Type 1 fonts. There are programs that change PFB (binary) fonts into PFA (ASCII) format (and back), that translate fonts into a disassembled human-readable format (and back), and that translate Macintosh Type 1 fonts into PFB or PFA (and back).
PostScript::CDCover generates a Postscript program that prints a CD cover and backlabel, with contents displayed as a tree of directories and files. The module ships with a stand-alone, ready-to-use script, pscdcover, that takes the directory tree of a CD-ROM as input and generates a cover from it. The output can be directly fed to a PostScript printer, but it is designed to be easily editable (should one wish to remove unwanted directory entries, for example).
Optar is a software codec that generates 2D bar codes for data storage on paper using a black and white laser printer and scanner. It fits 200kB on an A4 page, uses Golay forward error correction codes to ensure reliability, and can also be used to store data on photographic film.
xmlroff is a fast, multilingual, multi-platform XSL formatter that transforms XSL-FO documents (or any XML with an appropriate XSL stylesheet) into PDF or PostScript. It aims to excel at DocBook formatting, and it integrates easily with other programs and with scripting languages.
The CUPS Driver Development Kit (DDK) provides a suite of standard drivers, a PPD file compiler, and other utilities that can be used to develop printer drivers for CUPS and other printing environments. CUPS provides a portable printing layer for Unix-based operating systems. The CUPS DDK provides the means for mass-producing PPD files and drivers/filters for CUPS-based printer drivers.