PAPPL is a simple C-based framework/library for developing CUPS Printer Applications, which are the recommended replacement for printer drivers. It was specifically developed to support LPrint and a future Gutenprint Printer Application but is sufficiently general purpose to support any kind of printer or driver that can be used on desktops, servers, and in embedded environments.
PAPPL supports JPEG, PNG, PWG Raster, Apple Raster, and "raw" printing to printers connected via USB and network (AppSocket/JetDirect) connections. PAPPL provides an embedded IPP Everywhere™ service that provides access to printers locally or on your whole network.
PAPPL is licensed under the Apache License Version 2.0 with an exception to allow linking against GPL2/LGPL2 software (like older versions of CUPS), so it can be used freely in any project you'd like. If you want to support the development of this framework financially, please consider sponsoring me through Github. I am also available to do consulting and/or development through my company Lakeside Robotics (https://www.lakesiderobotics.ca).
My hope is that PAPPL will accelerate the adoption of IPP Everywhere™ and make it easier for people to support other IPP-based licensing programs like AirPrint™ and Mopria®.
PAPPL requires a POSIX-compliant host operating system such as Linux®, macOS®,
QNX®, or VxWorks®, a "make" utility that supports the include directive (like
GNU make), a C99-compatible C compiler such as GCC or Clang, and the
"pkg-config" utility. It also requires the following support libraries:
- Avahi 0.8 or later (except on macOS) for mDNS/DNS-SD support
- CUPS 2.2 or later for the CUPS libraries
- GNU TLS 3.0 or later (except on macOS) for TLS support
- JPEGLIB 9 or later for JPEG image support (optional for B&W printers)
- LIBPNG 1.6 or later for PNG image support (optional)
- LIBPAM for authentication support (optional)
- ZLIB 1.1 or later for compression support
Most development happens on a Mac, with testing on various Linux distributions and a Raspberry Pi Zero W to ensure that memory and CPU requirements remain low.
Documentation can be found in the "doc" and "man" directories.
The OpenPrinting group has written a tutorial showing how to migrate the
rastertohp driver from CUPS to a Printer Application using PAPPL, which can
be used as a recipe for migrating any CUPS driver. This example is available
in the hp-printer-app project and is also discussed in the PAPPL
documentation.
The OpenPrinting group is also developing a PostScript printer application using PAPPL to support the many otherwise unsupported PostScript and Ghostscript-based printers.
PAPPL is Copyright © 2019-2020 by Michael R Sweet.
This software is licensed under the Apache License Version 2.0 with an (optional) exception to allow linking against GPL2/LGPL2 software (like older versions of CUPS). See the files "LICENSE" and "NOTICE" for more information.
This software is based loosely on the "ippeveprinter.c" code from CUPS.