Compiler for Writing C Extensions for the Python Language

https://cython.org/

Data Acquisition abstraction library for snort 2.9+

https://www.snort.org/

POSIX-compliant implementation of /bin/sh

http://gondor.apana.org.au/~herbert/dash/

Datadog Agent: collect metrics and events from your systems and apps

https://www.datadoghq.com/

Datadog Agent Integrations

https://www.datadoghq.com/

Typeface that melts text and data visualisation

http://figs-lab.com/en/datalegreya

Small and fast AV1 decoder

https://code.videolan.org/videolan/dav1d

Manipulate db(3)'s btree(3) and hash(3) databases - NetBSD port

http://cvsweb.netbsd.org/bsdweb.cgi/src/usr.bin/db/

Oracle Berkeley DB, Release 18.1

https://www.oracle.com/database/berkeley-db/

Berkeley DB package, revision 4.8

http://www.oracle.com/us/products/database/berkeley-db/db/

Oracle Berkeley DB, revision 5.3

https://www.oracle.com/database/berkeley-db/db.html

Oracle Berkeley DB, revision 6.2

http://www.oracle.com/us/products/database/berkeley-db/db/

A distributed network benchmarking system

http://www.kusa.ac.jp/~yukio-m/dbs/

Message bus system for inter-application communication

http://www.freedesktop.org/Software/dbus

GLib bindings for the D-BUS messaging system

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

Distributed Checksum Clearinghouse bulk email detector

https://www.rhyolite.com/dcc/

Configuration database system for GNOME

https://wiki.gnome.org/Projects/dconf

Configuration database editor for GNOME

https://wiki.gnome.org/Projects/dconf

Update dynamic DNS entries

https://github.com/ddclient/ddclient

Command-line utility for converting a Debian .deb file to a .tar.gz

Install Debian base system into a directory

https://wiki.debian.org/Debootstrap

Model to synchronize multiple instances over DBus

https://launchpad.net/dee

Automated program/system tester

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

Bitstream Vera Fonts clone with a wider range of characters

https://dejavu-fonts.github.io/

Couple of command line utilities for working with desktop entries

https://www.freedesktop.org/wiki/Software/desktop-file-utils/

8086 development tools

http://homepage.ntlworld.com/robert.debath/

AMD and Intel CPUs microcode updates

Developer help browser for GNOME 3

http://www.imendio.com/projects/devhelp/

Tool to effectively maintain todo lists aimed at developers

http://swapoff.org/devtodo.html

Wonderful Sega Genesis/MegaDrive emulator

http://dgen.sourceforge.net/

KAME DHCP6 client, server, and relay

http://wide-dhcpv6.sourceforge.net/

Decode and diagnose sniffed DHCP packets

http://www.mavetju.org/unix/general.php

Disk Information Utility

https://diskinfo-di.sourceforge.io/

Diagram creation program, similar to Visio

https://live.gnome.org/Dia

Console Interface to configure ports

https://bitbucket.org/m1cro/d4p/

Simple english/german dictionary

http://www.de.freebsd.org/~wosch/dict/dict.cgi

Dict protocol (RFC 2229) server

http://www.dict.org/

GNU diff utilities

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

Monospace bitmap font, primarily aimed at programmers

http://www.donationcoder.com/Software/Jibz/Dina/

Open source video codec from the BBC

http://dirac.sourceforge.net/

Graphical diff tool

http://freecode.com/projects/dirdiff/

Client for managing and downloading certificate revocation lists

http://www.gnupg.org/aegypten2

Frontend to xgamma

http://gnu.ethz.ch/linuks.mine.nu/displaycalibrator/

Distribute compilation of C(++) code acrosss machines on a network

http://distcc.org

Extremely fast library for floating-point convolution

http://cr.yp.to/djbfft.html

DjVu base libraries and utilities

http://djvu.sourceforge.net/

FTP benchmark program

http://www.kegel.com/dkftpbench/

Another hyper make utility

http://code.google.com/a/apache-extras.org/p/dmake/

Portable debug memory allocation library

http://dmalloc.com/

X11 menu application designed for the dwm window manager

https://tools.suckless.org/dmenu