Problem
What does the term “opt” (as in the “opt” directory) imply? This directory is frequently found in Unix systems containing development tools.
Is it a contraction?
Asked by John Assymptoth
Solution #1
In the past, UNIX suppliers such as AT&T, Sun, DEC, and 3rd-party vendors utilized “/opt” to store “Option” packages, which were programs that you might have paid extra money for. On Berkeley BSD UNIX, I don’t recall seeing “/opt.” For self-installed software, they used “/usr/local.”
However, the true “meaning” of the various directories has always been a bit hazy. That’s probably a good thing, because if these directories had definite (and strictly enforced) semantics, there would be a plethora of various directory names.
“/opt/*” is described in the Filesystem Hierarchy Standard as follows:
On the other hand, it says about “/usr/local/*”:
“/usr/local/*” is now commonly used for installing locally produced software, potentially after changing setup parameters, and so on.
Answered by Stephen C
Solution #2
It’s commonly used to refer to optional add-on software packages, or anything that isn’t included in the basic system. It’s only used by a few distributions; others simply use /usr/local.
Answered by Dan
Solution #3
OPTional
It holds optional software and packages that you install that are not required for the system to run.
Answered by Justin808
Solution #4
Add-on software packages.
Details can be found at http://www.pathname.com/fhs/2.2/fhs-3.12.html.
Wikipedia has a description as well.
Its use may be traced back to the late 1980s, when it was included in System V UNIX as a standard feature. It’s now found in Linux, Solaris (which is SysV), OSX Cygwin, and other operating systems. Other BSD unixes (FreeBSD, NetBSD, and so on) tend to follow other conventions, thus you won’t see a /opt on a BSD system unless it’s run by someone who is more at ease in other contexts.
Answered by ghoti
Solution #5
It’s an acronym for ‘optional,’ and it’s used in various distros to refer to optional software.
Answered by digidigo
Post is based on https://stackoverflow.com/questions/12649355/what-does-opt-mean-as-in-the-opt-directory-is-it-an-abbreviation