Penny's OS 2.0 (S 17)

   
or QDOS or QiLinux
or Qimo or Q-Kernel
or QNX or QNX Neutrino
or Qomo or Qplus
or Qt Extended or Qtopia
or Quadros or Quantian
or Quark or QUARN
or Quetzal or QuickRAM
or QUNIX