Library for manipulating PNG images

http://www.libpng.org/pub/png/libpng.html

Open Source embedded SSL/TLS cryptographic library

http://polarssl.org/

Framework for controlling access to system-wide components

http://www.freedesktop.org/wiki/Software/PolicyKit

Small and fast caching web proxy

http://www.pps.jussieu.fr/~jch/software/polipo/

Framework for controlling access to system-wide components

https://www.freedesktop.org/wiki/Software/polkit/

Very fast, highly configurable POP3 server (fully RFC1939 compliant)

PDF rendering library

https://poppler.freedesktop.org/

Poppler encoding data

https://poppler.freedesktop.org/

GLib bindings to poppler

https://poppler.freedesktop.org/

Poppler's xpdf-workalike command line utilities

https://poppler.freedesktop.org/

Getopt(3) like library with a number of enhancements, from Redhat

http://freshmeat.net/projects/popt/

Console-based AIM client

http://dev.ojnk.net/

Portable cross-platform Audio API

http://www.portaudio.com/

Verifier for mports directory

Port searching tool that supports search by packing list files

http://people.freebsd.org/~vd/portsearch

Secure alternative to widely-used Sendmail

http://www.postfix.org/

New C++ interface for PostgreSQL

http://pqxx.org/

PostgreSQL database (client)

http://www.postgresql.org/

The most advanced open-source database available anywhere

http://www.postgresql.org/

PostgreSQL database (client)

http://www.postgresql.org/

The contrib utilities from the PostgreSQL distribution

http://www.postgresql.org/

The most advanced open-source database available anywhere

http://www.postgresql.org/

PostgreSQL database (client)

http://www.postgresql.org/

The contrib utilities from the PostgreSQL distribution

http://www.postgresql.org/

The most advanced open-source database available anywhere

http://www.postgresql.org/

A daemon that connects local terminal device to a terminal server

http://rnoc.urc.ac.ru/~anton/projects/pr/PR.html

Present protocol specification

Print extension headers

http://www.freedesktop.org/wiki/Software/xlibs

Local mail delivery agent

http://www.procmail.org/

Highly configurable FTP daemon

http://www.proftpd.org/

Data interchange format library

https://github.com/protocolbuffers/protobuf

New shell made entirely out of a Perl script

https://metacpan.org/release/psh

Conversion utility to convert Psion 5(MX) files into other formats

https://frodo.looijaard.name/project/psiconv

Utilities for manipulating PostScript documents

http://gershwin.ens.fr/vdaniel/Doc-Locale/Outils-Gnu-Linux/PsUtils/

GNU Portable Threads

http://www.gnu.org/software/pth/

GNU Portable Threads

http://www.gnu.org/software/pth/

Sound server for UNIX

http://pulseaudio.org/

Free Blizzard Battle.net emulation software

http://pvpgn.berlios.de

Fast and easy to use stand-alone template engine

https://jinja.palletsprojects.com/en/3.1.x/

Implements a XML/HTML/XHTML Markup safe string for Python

https://github.com/pallets/markupsafe

Access a MySQL database through Python

https://github.com/farcepest/MySQLdb1

Collection of tools for internationalizing Python applications

http://babel.pocoo.org/

Standard Python bindings to the Berkeley DB library

Python 2 bindings for Cairo

https://github.com/pygobject/pycairo

Python bindings for the D-BUS messaging system

https://dbus.freedesktop.org/doc/dbus-python/

DNS toolkit for Python

http://www.dnspython.org/

Python Documentation Utilities

https://docutils.sourceforge.io/

File I/O related functions and classes

http://www.livinglogic.de/Python/fileutils/

GData Python Client Library

https://github.com/google/gdata-python-client

Python bindings to the GNU dbm library (Python 3.10)