Similar to Doxygen

Darik's Boot and Nuke

DD-WRT

Deno (software)

Diff

Diff3

Discourse (software)

Docker (software)

Dolphin (file manager)

Dragon Player

Drupal

DSpace

DVD Flick

Device independent file format#DVI-to-PDF converters

Dvips

Eclipse (software)

Elasticsearch

EGS (program)

Emacs

Enlightened Sound Daemon

Erlang (programming language)