Utility to help to configure compiler and linker flags

https://git.sr.ht/~kaniini/pkgconf

Free clone of KlipFolio for GNUstep

http://www.collaboration-world.com/cgi-bin/project/index.cgi?pid=7

A plotting library and toolkit

http://www.gnu.org/software/plotutils/plotutils.html

Pre Make Kit, a sane replacement for autoconf

http://pmk.sourceforge.net/

WikiWikiWeb clone using PHP

https://www.pmwiki.org

Library for manipulating PNG images

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

Vorbis comment editor for GNUstep

https://www.eskimo.com/~pburns/Poe/

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

GNOME frontend to the PolicyKit framework

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/

GNOME frontend to the PolicyKit framework

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

Qt5 wrapper around Polkit libraries

http://projects.kde.org/projects/kdesupport/polkit-qt-1

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/

Interactive learning aid for pairs of words

http://popup.sourceforge.net/

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/

Java JDBC implementation for PostgreSQL

https://jdbc.postgresql.org/

New C++ interface for PostgreSQL

http://pqxx.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/

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

GNUstep workspace manager

http://www.nongnu.org/backbone/

Present protocol specification

Print extension headers

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

Barcode library for KDE

http://projects.kde.org/prison

Privoxy is a web proxy with advanced filtering capabilities

https://www.privoxy.org/

Local mail delivery agent

http://www.procmail.org/

Highly configurable FTP daemon

http://www.proftpd.org/

A development environment for GNUstep

http://www.gnustep.org/experience/ProjectCenter.html

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/