Similar to Mutter

Dbndns

Debbugs

Debian Conference

Debian Almquist shell

DesktopBSD

DigiKam

Dirac (video compression format)

DirectFB

Distcc

Doom Emacs

DOSBox

Droid (typeface)

Dvd+rw-tools

Ehcache

Embedded GLIBC

EmuTOS

Enigmail

Exim

Express.js

FabFi

Fedora Project

FLAC