Similar to SeaMonkey

Mir (software)

Mozilla Prism

Ninja (build system)

Nix (package manager)

Node.js

NoteEdit

Ns (simulator)

Ocrad

OGRE

Open Babel

OpenCV

OpenFOAM

OpenJDK

OpenSceneGraph

PCSX2

Phusion Passenger

PLUMED

Point Cloud Library

POV-Ray

PowerDNS

Project64

PyQt

QGIS

Qt (software)

Qtractor

Quassel IRC

Quite Universal Circuit Simulator