GNUlpr version 1.0 is a complete printing system based on LPR, and provides support for printer-specific options, GUI tools, and autoconfiguration. The 1.1 tree is a completely re-thought printing system. Rather than creating an all-powerful spooling daemon, it constructs a pipeline of "filter" programs to perform tasks (spooling, data stream type conversion, authentication, network protocols, etc.).
npadmin is a command line tool to administer network printers. It is based on the concepts of JetAdmin and other vendor's tools but is designed to be scriptable. It uses SNMP to query the common printer MIB (RFC 1759) and return information about the printer. There is a surprising amount of information available in the common printer MIB and since the vendors all use their private MIBs, this appears to be the only tool that makes it available.