The New Hacker's Dictionary

open switch // n.

[IBM: prob. from railroading] An unresolved question, issue, or problem.

operating system // n.

[techspeak] (Often abbreviated 'OS') The foundation software of a machine; that which schedules tasks, allocates storage, and presents a default interface to the user between applications. The facilities an operating system provides and its general design philosophy exert an extremely strong influence on programming style and on the technical cultures that grow up around its host machines. Hacker folklore has been shaped primarily by the Unix, ITS, TOPS-10, TOPS-20/TWENEX, WAITS, CP/M, MS-DOS, and Multics operating systems (most importantly by ITS and Unix).

optical diff // n.

See vdiff.

optical grep // n.

See vgrep.

optimism // n.

What a programmer is full of after fixing the last bug and before discovering the next last bug. Fred Brooks's book "The Mythical Man-Month" (See "Brooks's Law") contains the following paragraph that describes this extremely well:

All programmers are optimists. Perhaps this modern sorcery especially attracts those who believe in happy endings and fairy godmothers. Perhaps the hundreds of nitty frustrations drive away all but those who habitually focus on the end goal. Perhaps it is merely that computers are young, programmers are younger, and the young are always optimists. But however the selection process works, the result is indisputable: "This time it will surely run," or "I just found the last bug.".

See also Lubarsky's Law of Cybernetic Entomology.

Oracle, the //

The all-knowing, all-wise Internet Oracle rec.humor.oracle), or one of the foreign language derivatives of same. Newbies frequently confuse the Oracle with Oracle, a database vendor. As a result, the unmoderated rec.humor.oracle.d is frequently crossposted to by the clueless, looking for advice on SQL. As more than one person has said in similar situations, "Don't people bother to look at the newsgroup description line anymore?" (To which the standard response is, "Did people ever read it in the first place?")