OpenSolaris

Solaris LP code usr/src/cmd/lp	Original Solaris LP code base.  Contains spooler, postscript filters, terminfo files, PAPI interface code, and more
Solaris PostScript filters usr/src/cmd/lp/postscript	Base postscript filters
Solaris LP spooler usr/src/cmd/lp/cmd/lpsched	Base Solaris LP spooler
PAPI Solaris LP interface code usr/src/cmd/lp/lib/papi	Support for applications using the PAPI to interact with the Solaris LP spooler
Legacy RFC-1179 to lpsched translator usr/src/cmd/lp/cmd/bsd-adaptor	Support for translating legacy protocol listener requests to lpsched messages.
Legacy backend processing scripts usr/src/cmd/lp/model/[net]standard	standard/netstandard interface scripts use for several years to perform final job processing and send job data to local and network attached printers
Modified backend processing scripts usr/src/cmd/lp/model/*_foomatic	modified versions of the *standard interface scripts that use foomatic for final job data transformation to a printer ready format.
New backend processing script usr/src/cmd/lp/model/uri	New backend processing script that optionally uses foomatic for final job data transformation to a printer ready format and uses helper modules (like smbspool) to send job data to a local or network attached printer.
Local Printer I/O handler usr/src/cmd/lp/model/lp.cat.c	incredibly simplistic local printer I/O handler
Local PostScript Printer I/O handler usr/src/cmd/lp/filter/postscript/postio	more sophisticated local printer I/O handler
Network Printer I/O handler usr/src/cmd/lp/model/netpr	network printer I/O handler for printers that support raw sockets or "lpd" protocol
Solaris Client code usr/src/cmd/print	Client comands (lp/lpr/lpstat/lpq/cancel/lprm/...), in.lpd rfc-1179 protocol listener, print manager, and more.  The client commands will be replaced with PAPI based implementations in short order.
Legacy RFC-1179 listener usr/src/cmd/print/gateway	Legacy RFC-1179 protocol listening service that will ultimately be replaced with a PAPI based version.
Solaris PrintMgr code usr/src/cmd/print/printmgr	JAVA based configuration management GUI that eases queue creation/modification.
Printer probe usr/src/cmd/print/printer-info	A program to probe USB and ECPP connected printers for Make/Model information used by the printmgr.
Various scripts usr/src/cmd/print/scripts	Various scripts including retreival of information from the PPD cache file used by the printmgr.
Solaris common client library usr/src/lib/print	Common code for client commands and client side management commands.  As PAPI based client commands integrate, much of this code will dissappear.
Name Service Switch support usr/src/lib/nsswitch/*/common/getprinter.c	Name Service Switch support for client commands to get configuration data from a variety of sources including network repositories

PAPI Shared routines papi/source/libpapi-common/	Common routines used by most, if not all, of the PAPI support.  This includes an implementation of the attributes interface and several helper functions
PAPI Dynamic library papi/source/libpapi-dynamic/	PAPI library that provides names service lookup support and redirection to alternate PAPI implementations.
PAPI RFC-1179/LPD support papi/source/libpapi-lpd/	PAPI support for interacting with RFC-1179/LPD protocol servers.
PAPI CUPS support papi/source/libpapi-cups/	PAPI support for interacting with CUPS spooler using libcups interfaces.
PAPI IPP support papi/source/libpapi-ipp/	PAPI support for interacting with IPP based protocol servers.  This includes servers like Solaris LP, CUPS, WinXP, and more.
Core IPP protocol library papi/source/libipp-core/	IPP encoding/decoding and on the wire support
IPP listening service operations library papi/source/libipp-listener/	Server side IPP operations support
Apache IPP listener module papi/source/mod_ipp	Apache glue module for passing IPP requests to the IPP listener library and ultimately the print service.  (supports both Apache 1.X and 2.X)
BSD & SYSV commands papi/source/bsd-sysv-commands	Replacement implementations of common BSD & SYSV print commands using the PAPI for print service interaction. (lpr/lpq/lprm/lpc) (lp/lpstat/cancel/accept/reject/enable/disable)
Example code using the PAPI papi/source/examples/	Sample code that shows how to use the PAPI
PAPI specification and documentation papi/docs	PAPI specification and documentation about code in the source base.

GhostScript http://www.cups.org/espgs/index.php	ESP Ghostscript 7.07.1 converts PostScript job data to a variety of printer ready formats.
a2ps http://www.gnu.org/software/a2ps/	a2ps 4.13 converts from various formats to PostScript
gimp-print (aka gutenprint) http://gimp-print.sourceforge.net/ http://sourceforge.net/projects/gutenprint/	gimp-print 4.2.6 support for a variety of different printers used with GhostScript
HPIJS http://hpinkjet.sourceforge.net/	hpijs 1.6 support for HP printers used with GhostScript
psutils http://freshmeat.net/projects/psutils/	psutils p17 support for handling reasonably behaved PostScript files.
ImageMagick http://sourceforge.net/projects/imagemagick/	ImageMagick 5.4.7 support for image format conversion
Foomatic http://linuxprinting.org/foomatic.html	Foomatic 3.0.2 is the document format converter from hell that makes use of all of these components, as well as annotated PPD files, to convert print job data to a printer ready format and folds in capability information on the way out to the printer.
Foomatic ppd http://linuxprinting.org/foomatic.html	Foomatic annotated PPD files with instructions on how to convert to a printer ready format and fold in printer capability information. from  2004-03-04
SAMBA http://samba.org/	Samba 3.0.4 provides support for Windows clients to access printers on a Solaris host and Solaris a means of sending print job data to printers  connected to Windows hosts using native windows protocols.
GNOME (libgnomeprint) http://cvs.gnome.org/.../libgnomeprint/.../PAPI/	GNOME Application support to print via the PAPI.
Apache http://www.apache.org/	Apache Web server used for IPP support