Similar to Boost_C++ライブラリ

Open Babel

OpenFOAM

OpenJDK

OpenOffice.org

PackageKit

PCSX2

Phonon (software)

Phusion Passenger

PLUMED

Point Cloud Library

Poppler (software)

POV-Ray

PowerDNS

PPSSPP

Project64

PyQt

QBittorrent

QGIS

Qt (software)

Qt Creator

Qtractor

Quassel IRC

Quite Universal Circuit Simulator

ReactOS

Rosegarden

RPCS3

SAGA GIS

Cube 2: Sauerbraten