What does DOS stand for?

What does DOS mean?

DOS	Denial Of Service Computing » Networking
DOS	Denial Of Service Computing » Drivers
DOS	Denial Of Service Internet
DoS	Denial of Service Computing » General
DOS	Department of State Governmental » Military
DOS	Department of State Governmental » US Government
DOS	Department of State Business » International Business
DOS	Department of State Academic & Science » Meteorology
DOS	Department Of State Academic & Science » Ocean Science
DOS	Density Of States Academic & Science » Electronics
DOS	Disk Operating System Governmental » Military
DOS	Disk Operating System Community » Media
DOS	Disk Operating System Computing » Software
DOS	Disk Operating System Computing » Networking
DOS	Disk Operating System Computing » General
DOS	Democratic Opposition Of Serbia Governmental » Politics
DOS	Dirty Operating System Miscellaneous » Funnies
DOS	Denial Of Services Miscellaneous » Unclassified
DOS	Distributed Operating System Miscellaneous » Unclassified
DOS	Defunct Operating System Miscellaneous » Funnies
DOS	Disk Operation System Miscellaneous » Unclassified
DOS	Dual Operating System Computing » Software
DOS	Denail Of Service Miscellaneous » Unclassified
DOS	Disk Operating Systems Miscellaneous » Unclassified
DOS	Dance Of Sound Community » Performing Arts