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

A small and fast caching web proxy

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

Framework for controlling access to system-wide components

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

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

PDF rendering library

http://poppler.freedesktop.org/

Poppler encoding data

http://poppler.freedesktop.org/

Glib bindings to poppler

http://poppler.freedesktop.org/

Poppler's xpdf-workalike command line utilities

http://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 (with OpenLDAP support)

https://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/google/protobuf

New shell made entirely out of a Perl script

http://search.cpan.org/dist/psh/

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

http://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

http://jinja.pocoo.org/

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

https://pypi.python.org/pypi/MarkupSafe/

Access a MySQL database through Python

http://sourceforge.net/projects/mysql-python/

Collection of tools for internationalizing Python applications

http://babel.pocoo.org/

Standard Python bindings to the Berkeley DB library

Python 2 bindings for Cairo

http://cairographics.org/

Python2 bindings for the D-BUS messaging system

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

DNS toolkit for Python

http://www.dnspython.org/

Python Documentation Utilities

http://docutils.sourceforge.net/

File I/O related functions and classes

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

GData Python Client Library

http://code.google.com/p/gdata-python-client/

Python bindings to the GNU dbm library