Extremely fast library for floating-point convolution

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

DjVu base libraries and utilities

http://djvu.sourceforge.net/

Domainkeys filter for Postfix

http://jason.long.name/dkfilter/

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

Tool for dumping DMI (SMBIOS) contents in human-readable format

https://www.nongnu.org/dmidecode/

Distributed.net distributed computing project client

http://www.distributed.net/

Lightweight DNS forwarder, DHCP, and TFTP server

http://www.thekelleys.org.uk/dnsmasq/doc.html

Simple sudo alternative to run commands as another user

https://github.com/slicer69/doas/

Meta-port for the different versions of the DocBook DTD

http://www.oasis-open.org/docbook/

DocBook SGML DTD

http://www.oasis-open.org/docbook/

DocBook SGML DTD into nroff/troff -man macros converter

https://www.oasis-open.org/docbook/tools/dtm/

Generates various output formats from DocBook SGML documents

http://sources.redhat.com/docbook-tools/

DocBook XML DTD

https://www.oasis-open.org/docbook/

DocBook W3C XML Schema

https://www.oasis-open.org/docbook/xmlschema/1.0b1/

XSL DocBook stylesheets

http://docbook.sourceforge.net/projects/xsl/

Namespace-aware DocBook XSLT stylesheets

http://docbook.sourceforge.net

Emacs lisp modules for editing DocBook documents

http://nwalsh.com/emacs/docbookide/

DOCSIS(tm) binary configuration file encoder/decoder

https://github.com/rlaager/docsis

Command-line DNS client

https://dns.lookup.dog/

DNS-over-HTTP server proxy

https://github.com/jedisct1/rust-doh

Doom data files (Doom, Doom II, Hexen, Heretic and Strife)

Complete Doom-based game IWAD that is Free Software

http://freedoom.sf.net/

Improved and extended version of Doom

http://doomlegacy.sourceforge.net/

Emulator of a PC with DOS

http://dosbox.sourceforge.net/

Simple, powerful configuration-file parser

https://github.com/williamh/dotconf

Binary-decimal and decimal-binary routines for IEEE doubles

https://github.com/google/double-conversion

Doulos SIL TrueType font collection

http://scripts.sil.org/cms/scripts/page.php?item_id=DoulosSILfont

Doulos SIL TrueType font collection, compact variant

http://scripts.sil.org/cms/scripts/page.php?item_id=DoulosSILfont

Secure, fast and powerful IMAP and POP3 server

https://www.dovecot.org/

Sieve plugin for the Dovecot 'deliver' LDA and LMTP

https://wiki2.dovecot.org/Pigeonhole

Documentation system for C, C++, and other languages

https://www.doxygen.org/

DRM modules for the linuxkpi-based KMS components

https://github.com/freebsd/drm-kmod

The Droid typeface family

https://www.droidfonts.com/

Database driven web content management system (CMS)

https://www.drupal.org/

Database driven web content management system (CMS)

https://www.drupal.org/

Database driven web content management system (CMS)

https://www.drupal.org/

Database driven web content management system (CMS)

https://www.drupal.org/

Qt client for DSBMD that lets you mount media, and more

https://github.com/mrclksr/DSBMC

Media mounting daemon

https://github.com/mrclksr/DSBMD

API for audio processing plugins

http://dssi.sourceforge.net/

DSSSL stylesheets for the DocBook DTD by Norman Walsh

http://sourceforge.net/projects/docbook/

Device Tree Compiler

https://git.kernel.org/cgit/utils/dtc/dtc.git

Spawns dhclients for a dual-stack network

Embeddable Javascript engine

https://duktape.org/

Embeddable Javascript engine (shared lib)

https://duktape.org/

Python implementation of the Git file formats and protocols

https://www.dulwich.io/

English to Thai dictionary for GNUstep

http://www.eskimo.com/~pburns/Dictionaries/