> In case you weren't aware Wine is not an emulator, it is a compatibility layer.
Ehhh. I know it’s in the name, but I feel like the significance is debatable. It’s not a CPU emulator, true. It is emulating calls, which is emulation of a sort.
Usually when you say "emulator" people think there's an inherent performance hit because of a fetch-decode-execute interpreter loop somewhere. Reimplementations of things don't have that performance hit even though they are lumped under the same umbrella as actual interpreters and recompilers.
Related note: if WINE is an emulator why isn't Linux or GNU? They both reimplement parts of UNIX, which was even more proprietary than Windows is today.
On most of these architectures the software eventually executes as x86 machine code, and the distance between x86 machine code and the actual processes inside a modern CPU implementing the x86 code set is so vast you can call a modern CPU an "x86 emulator built in hardware."
I mean, it depends on the context. I don't think it would be wrong to say that Linux "emulates a UNIX environment" or some such, which is closer to what OP actually wrote about Wine.
You've probably used a "terminal emulator" at some point today. ;)
In regular joe-schmo parlance, an emulator would be something that translates a hardware machine into software that is run on a different machine. Hardware being the important word here. Performance has nothing to do with how people use the term emulator in regular parlance.
That's still emulating the underlying API, and accepted usage of the word. Much like the FreeBSD linux emulator translates linux syscalls into FreeBSD ones.
You're exactly right, and the Wine project agrees.
> That said, Wine can be thought of as a Windows emulator in much the same way that Windows Vista can be thought of as a Windows XP emulator: both allow you to run the same applications by translating system calls in much the same way. Setting Wine to mimic Windows XP is not much different from setting Vista to launch an application in XP compatibility mode.
> [...]
> "Wine is not just an emulator" is more accurate. Thinking of Wine as just an emulator is really forgetting about the other things it is. Wine's "emulator" is really just a binary loader that allows Windows applications to interface with the Wine API replacement.
This is all really just a philosophical question as to how you choose to use the word. It's the same as people who get in a twist over every game with procedural generation and permadeath being called a "Roguelike" even though that particular subgenre used to be more specific to turn-based RPGs with procedural generation, permadeath and total loss of all progress between runs.
People who came into using the term earlier tend to think of it more narrowly, but colloquial use of the term has drifted to mean something more generic, e.g. "emulation" used to mean "making one piece of hardware pretend to be another", but now can sometimes just mean, "when one thing acts like another at all".
In this case, however, the term "to emulate" predates microprocessors, so it clearly can't have ever referred exclusively to ISA translation!
"Emulator" might be a more recent term—it would be interesting to see the etymology, actually—but it's reasonable to conclude that anything which "emulates" must be an "emulator". (Also, OP didn't actually use the word "emulator".)
Saying wine is an emulator is as wrong as saying docker (on linux) is a virual machine, even though you could say it allows you to run a “virtual environment” in the same hand-wavy way you're using the word “emulating” in your sentence.
> To imitate the function of (another system), as by modifications to hardware or software that allow the imitating system to accept the same data, execute the same programs, and achieve the same results as the imitated system.
It's the exact same way its used by FreeBSD for its linux compatibility layer. It's the same way that Wine even uses in their FAQ.
> That said, Wine can be thought of as a Windows emulator in much the same way that Windows Vista can be thought of as a Windows XP emulator: both allow you to run the same applications by translating system calls in much the same way. Setting Wine to mimic Windows XP is not much different from setting Vista to launch an application in XP compatibility mode.
> [...]
> "Wine is not just an emulator" is more accurate. Thinking of Wine as just an emulator is really forgetting about the other things it is. Wine's "emulator" is really just a binary loader that allows Windows applications to interface with the Wine API replacement.
The problem with this definition is that it's so broad it encompasses many many things that are never talked about as “emulators”. By this definition, Docker is an emulator, a VM is an emulator, an x86_64 CPU is an emulator (because it “emulates“, in the broadest sense, x86), a C compiler is an emulator (“emulating” the PDP-11 on modern hardware), etc.
Even your own quote reveals the issue:
> > That said, Wine can be thought of as a Windows emulator in much the same way that Windows Vista can be thought of as a Windows XP emulator
Yet nobody talks about the latest Windows as being an emulator for older windows …
In short, this definition is akin to defining humans as “bipeds without feather”, we definitely fit this definition but it's way too broad to be useful.
Related note: if WINE is an emulator why isn't Linux or GNU? They both reimplement parts of UNIX, which was even more proprietary than Windows is today.