Here's a short story:

Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. 

Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties from the late 1970s, leading to a variety of both academic and commercial variants of Unix from vendors such as the University of California, Berkeley (BSD), Microsoft (Xenix), IBM (AIX) and Sun Microsystems (Solaris). AT&T finally sold its rights in Unix to Novell in the early 1990s, which then sold its Unix business to the Santa Cruz Operation (SCO) in 1995, but the UNIX trademark passed to the industry standards consortium The Open Group, which allows the use of the mark for certified operating systems compliant with the Single UNIX Specification (SUS). Among these is Apple's macOS, which is the Unix version with the largest installed base as of 2014. 

From the power user's or programmer's perspective, Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy", meaning that the operating system provides a set of simple tools that each perform a limited, well-defined function, with a unified filesystem as the main means of communication and a shell scripting and command language to combine the tools to perform complex workflows. Aside from the modular design, Unix also distinguishes itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language that allowed Unix to reach numerous platforms. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: what OS is the article about?
Guess: Unix
Confidence: <appropriate level of confidence in this guess>

Question: what is it?
Guess: a family of multitasking, multiuser computer operating systems
Confidence: <appropriate level of confidence in this guess>

Question: where did it come from?
Guess: the original AT&T Unix
Confidence: <appropriate level of confidence in this guess>

Question: when did they let other work on their OS?
Guess: in the late 1970s
Confidence: <appropriate level of confidence in this guess>

Question: are there different versions?
Guess: Yes
Confidence: <appropriate level of confidence in this guess>

Question: how do they differ?
Guess: some are academic and others commercial
Confidence: <appropriate level of confidence in this guess>

Question: who released some versions?
Guess: the University of California, Berkeley
Confidence: <appropriate level of confidence in this guess>

Question: what was their flavor named?
Guess: (BSD)
Confidence: <appropriate level of confidence in this guess>

Question: who else?
Guess: Microsoft
Confidence: <appropriate level of confidence in this guess>

Question: what did they call theirs?
Guess: (Xenix)
Confidence: <appropriate level of confidence in this guess>

Question: anyone else?
Guess: IBM  and Sun Microsystems
Confidence: <appropriate level of confidence in this guess>

Question: what were their flavors named?
Guess: (AIX) and (Solaris)
Confidence: <appropriate level of confidence in this guess>

Question: who bought the rights to from the phone company?
Guess: Novell
Confidence: <appropriate level of confidence in this guess>

Question: when?
Guess: in the early 1990s
Confidence: <appropriate level of confidence in this guess>

Question: did they resell it?
Guess: Yes
Confidence: <appropriate level of confidence in this guess>

Question: when?
Guess: 1995
Confidence: <appropriate level of confidence in this guess>

Question: who bought it?
Guess: SCO
Confidence: <appropriate level of confidence in this guess>

Question: is that an acronym?
Guess: Yes
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: what does it stand for?

the Santa Cruz Operation