O

• Ob-
• Obfuscated C Contest
• obi-wan error
• Objectionable-C
• obscure
• octal forty
• off the trolley
• off-by-one error
• offline
• ogg
• -oid
• old fart
• Old Testament
• on the gripping hand
• one-banana problem
• one-line fix
• one-liner wars
• ooblick
• OP
• op
• open
• open source
• open switch
• operating system
• operator headspace
• optical diff
• optical grep
• optimism
• Oracle, the
• Orange Book
• oriental food
• orphan
• orphaned i-node
• orthogonal
• OS
• OS/2
• OSS
• OT
• OTOH
• out-of-band
• overclock
• overflow bit
• overrun
• overrun screw
• owned