Penny's OS 2.0 (S 19)

     

or SaaS or Sabayon Linux 

or Sabily or SABRE
or Sacix or Sage
or Saguaro or Salgix

or Salix OS or Salvare
or Salvo or SAM
or Samhain Linux or Sanos
or Santa Fe or The Sapphire Project
or Sartoris Microkernel or SauverOs

or SAX or ScaraOS 

or Scientific Linux or Scientific Linux Fermi
or SCI.Linux or SCIOPTA RTOS
or SCO Open Desktop or SCO OpenServer
or SCOPE or ScorchOS
or Scos or ScottsNewOS
or SCO UNIX or SCO Unixware

or SCO XENIX or Scout
or SCP or SCP-DOS
or SCP-IBE or SCP-1700

or ScreenOS or ScrudgeWare
or SDOS or SDPOS

or SECCOS or Securepoint Os 

or SEL 810A/810B OS or Sendla OS 

or Sentry Firewall or SeOS 

or Sequent or SHARE 

or ShareNet or S.Ha.R.K. 

or SharpOS or ShawnOS 

or Shift Linux or Shinux 

or SHR or SIBO

or sidux or SIGMA 7 OS
or SilveOS or SimpleAVROS
or Simplis or SimplyMEPIS
or Sinclair QDOS or Singularity
or SINIX or SINTRAN
or SIPROS or Sirius RTOS
or 64 Studio or Skolelinux
or SkyOS or Slack/390
or Slackintosh or Slackware
or Slamd64 or SLAMPP
or Slavix or Slax 

or Slikware or SliTaz 

or Slix or Slo-Tech Linux 

or SLS or SLYNUX GNU 

or Smallfoot or SmartDOS 

or SME Server or SmoothWall 

or SMP or SMS

or sMultiTA or $murf oS
or SNAPPIX or Snøfrix
or SOBS or SODA
or SODS/OS or SOFriki
or Softlanding or Solaris
or Solar_OS or Solbourne UNIX

or SOLO or Sombrero

or SONaFR or S1

or SOOS or Sorcerer

or SORIX or SOS 

or SOT Linux or Source Mage

or SOX or Soyombo

or SPACE or SPART

or SpartaDOS or Spectra Linux

or SPEEDOS or SPHERE

or SphinxOS or Spice 

or Spice/MT or SPIN 

or Spinix or SPIX
or Splack or Splashtop
or The Spoon Microkernel or SPOX

or SPP-UX or Spri
or Spring or Sprite

or SP6800 or SQOS
or SqueakNOS or SSB-DOS
or SSP or SSS-PC
or Stable Hybrid Release or Stampede
or STARCOS or StarOS
or STARPLEX II  or STARSYS
or Start.com or Static OS
or STD or Stellix

or Sting or STOP

or Stonegate or Storm Linux
or STRATUS or Stratus VOS
or StreamBOX or StreamOS
or StressLinux or Stupid
or STUX or STX 

or Subsumpt or SUE

or Sugar on a Stick or Sumo
or SUN or SUNIX
or SUNMOS or SunOS
or Sun Linux or SunriseOS

or Sun Solaris or Sunwah Linux 

or SuperDOS or SuperGamer
or Super OS or Super ubuntu
or SUPER-UX or SuSe

or SVM or SVR

or SVS or SyCODE Platform
or Syllable Desktop or Symbian OS
or Symbian Platform or Symbolics Genera 

or SymbOS or Symobi 

or Symphony OS or Synapse 

or Synthesis or Synthetix 

or SYSEX or  SysPak OS
or System B or System 1 

or SystemRescueCD or System 6

or System 2 or System V