The Windows 95 spooler and Windows NT spooler are similar in many ways. One important difference is that in Windows NT the router, local print provider (local spooler), default print processor and default monitor components were each packaged in a separate DLL. In Windows 95, for performance reasons, the default router, local print provider, and port monitor are packaged in one DLL (SPOOLSS.DLL). If you decide to add a print processor, port monitor, or language monitor to the Windows 95 spooler subsystem, you will have to build a separate DLL that is callable by the spooler DLL. Guidelines on how to do this for print processors and port monitors are given in About Print Processors, About Port Monitors, and About Language Monitors. Instructions on how to install these DLLs, either by calling Win32 APIs or adding extensions to printer .INF files are given in Installing Printer Support. Sample source code for a print processor, port monitor, and language monitor are in the SAMPLES directory of the DDK.
Highlights of other similarities and differences between the Windows NT and Windows 95 spooler include: