Similar to DOSBox

Nix (package manager)

Node.js

NoteEdit

Notepad++

Ns (simulator)

Ocrad

OGRE

Open Babel

OpenCV

OpenFOAM

OpenJDK

OpenSceneGraph

Phusion Passenger

PLUMED

Point Cloud Library

POV-Ray

PowerDNS

PyQt

Qt (software)

Qtractor

Quassel IRC

Quite Universal Circuit Simulator

ReactOS

RocksDB

Rosegarden

RTorrent

Cube 2: Sauerbraten