PPR is a spooler for PostScript printers. It supports PPD files, and provides operator alerts, job result messages, and error recovery. It is integrated with Netatalk, CAP60, Samba, and Ghostscript. It has command line and web interfaces.
OpenPrinting provides a set of specifications and implementations of software focused on creating standardized, scalable printing components for Linux, Solaris, or any system with a set of POSIX interfaces.