Similar to GnuCash

Amaya (web editor)

Vim (text editor)

ARToolKit

MPlayer

OpenMM

Audacity (audio editor)

Oniguruma

CURL

Xine

Compiz

Samba (software)

GGPO

CinePaint

Shadowsocks

Squirrel (programming language)

SPICE

Darktable

Dovecot (software)

Tesseract (software)

Tor (network)

Dokan Library

Perl

Bacula

Bash (Unix shell)

HandBrake

Varnish (software)

BusyBox

Praat