From Black Ice Software:
The Black Ice LPD Manager Server is a LPD Print Server which receives print files from UNIX, Linux, MAC and Windows host systems via TCPIP and print them to networked, local or shared printer. Black Ice LPD Manager Server works as service and listens for requests on default TCP port 515 named LPR/LPD (Line Printer Remote/Line Printer Daemon) which is a TCP/IP printing protocol and network print server. Originally developed for Berkeley Unix (BSD Unix), LPR/LPD was the de facto standard for Unix printing prior to LPRng, IPP and CUPS. Used in conjunction with a printer driver, the LPR/LPD server queues the files and prints them when the printer becomes available. BiLPDManager Server can support multiple printers, in which case, the client identifies the intended printer by its queue name. In order to provide a complete printing system, LPR/LPD is used with a printer driver that converts the data into the command format required by the printer. Many different queue names may exist in BiLPDManager Server, with each queue having unique settings. BiLPDManager Server have the option to automatically create a new queue when a print job with an unknown queue name is received.