> 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.
The creators also would not call virtual machines emulators because they don't translate CPU instructions, which is their narrow criteria for "emulator" that nobody else seems to use.
> is their narrow criteria for "emulator" that nobody else seems to use.
Except the people actually writing or talking about real “emulators”. You know, for things like NES or Gameboy on x86, x86 on WASM, etc.
Sure, you can argue that VMs or Wine are emulators in the broadest sense, but then I could argue that your CPU is an emulator too since it doesn't really runs ASM, and with that very loose meaning almost anything computers related is an emulator. And in practice that's never what people mean when we're talking about an emulator. (Even this thread started with the wrong postulate that WINE must have incurred a performance penalty because the commented believed it was an emulator).
When I was at Interactive Systems Corporation in the mid to late'80s and we were porting System V Release 3 to the 386 for AT&T, we wrote a Wine-like program called i286emul to run 286 System V Release 2 binaries. We and AT&T called it an emulator [1].
Later AT&T and Microsoft and Sun were involved in various projects to merge features from System V R3, BSD, SunOS, and XENIX into System V R4. As part of that they wanted a way to run 286 XENIX binaries, and Microsoft contracted with Interactive for that. We wrote another Wine-like program for that called x286emul. We and Microsoft called it an emulator too [2]
The XENIX emulator led to the stupidest meeting I have ever had to attend. Microsoft said there was an issue with the kernel that could not be resolved over the phone or email. So me and the other guy working on x286emul had to go to Microsoft for a meeting.
A flag needed to be added to the process data structure that would tell the kernel to make some slight changes to a system call or two, due to some differences between System V and XENIX. It was something like XENIX having separate error codes for some things System V rolled into one, or something like that.
The meeting was about how to set/clear that flag. Microsoft wanted to know if we preferred that it be done as a new flag to an existing system call or if a new system call should be added. I looked at the other guy from Interactive and said something like "A flag's fine for me", he said he agreed. We said "flag" to Microsoft, and the meeting ended.
That couldn't have been handled by phone or email?
Things like Wine used to be called emulator, but this usage fell out of fashion a while ago. Now the word “emulator” has been generally refined to mean a (inherently slow) hardware emulator, and most of the compatibility layers explicitly market themselves as not being emulators: “Wine is not an emulator” “Rosetta isn't an emulator”, “x86 compatibility mode is not an emulator”, “virtualization isn't emulation”, and so on.
And even the starting comment on that thread seems to abide by this definition, as it complains about some (imaginary) emulation overhead when using Wine.
Languages changes overtime as usages evolve: when 80286 was released, the French word «baiser» still meant “to kiss” for most people, now it means “to fuck”.
Every new user seems to think Wine is an emulator, and plenty still after, so I don't believe it's out of fashion. If they don't, it's only because someone tried to make them feel dumb about it with the WINE acronym, which seems to exist because so many people call it an emulator. Maybe if that many people are mistaken, they're actually right.
I especially don't know who's calling Rosetta 2 "not an emulator," given that it's software-emulating x86 arch and actually comes with a noticeable slowdown, not that emulators need to have big overhead.
Yes, those people are writing hardware emulators. Doesn't mean they're the only "real" kind.
As for my Intel CPU, it isn't pretending to be another kind of CPU. Intel makes a leading implementation of x86. Wine follows Microsoft's Windows implementation and translates to Linux calls, and the entire point is so you can run programs intended for Windows on Linux instead. You can get relative about it, but it's not really, they're clearly different. Either way, doesn't support WINE's acronym.
> Yes, those people are writing hardware emulators. Doesn't mean they're the only "real" kind.
They're the only kind that doesn't involve a super broad definition of what the word “emulation” means (so broad that most computing actually fits in this definition).
> As for my Intel CPU, it isn't pretending to be another kind of CPU.
Until one day you realize that you can run an x86 program on a 64 bit CPU (but fortunately, this isn't done through “emulation” proper either).
> Until one day you realize that you can run an x86 program on a 64 bit CPU (but fortunately, this isn't done through “emulation” proper either).
It's reasonable to call that emulation if there's a separate layer for it translating to/from x86-64, rather than the hardware specifically supporting -32. My CPU isn't doing that cause I'm not running 32-bit software on macOS.
The Wii emulator is emulating the whole system including the CPU; WINE describes itself as not an emulator specifically because it's not doing anything about the CPU (hence not working on ARM Linux without extra work).
(I'm not 100% sold on this; I think "CPU emulator" and "ABI emulator" are both reasonable descriptions, albeit of different things, but that's the distinction that the WINE folks are making.)
By any well-known definition of an emulator, like https://en.wikipedia.org/wiki/Emulator, Wine is an emulator. It's emulating a Windows system to Windows programs. It's not emulating hardware is all. That WINE acronym, other than being a slightly annoying way to correct people, is wrong. Reminds me of Jimmy Neutron smartly calling table salt "sodium chloride" when really he's less correct than the layman he's talking to, since there are additives.
According to the Wikipedia link given, emulation is for host and target computer systems. In a computing context, 'emulate' is not a synonym for 'impersonate' - it describes an approach for a goal.
Wine does not aim to emulate a "Windows computer system" (aka a machine which booted into Windows). For instance, it doesn't allow one to run windows device drivers. WINE is taking an approach that ultimately means it is doing a subset of what is possible with full emulation (hopefully in return going much faster).
To put it another way, a mobile phone app with a HP49 interface that understands RPN is not necessarily a calculator emulator. It could just be an app that draws a calculator interface and understands RPN and some drawing commands. It doesn't necessarily have the capability to run firmwares or user binaries written for the Saturn processor.
The people who wrote Wine thought it was an emulator. Their first idea for a name was "winemu" but they didn't like that, then thought to shorten it to "wine".
The "Wine is not an emulator" suggestion was first made in 1993, not because Wine is not an emulator but because there was concern that "Windows Emulator" might run into trademark problems.
Eventually that was accepted as an alternative meaning to the name. The Wine FAQ up until late 1997 said "The word Wine stands for one of two things: WINdows Emulator, or Wine Is Not an Emulator. Both are right. Use whichever one you like best".
The release notes called it an emulator up through release 981108: "The is release 981108 of Wine, the MS Windows emulator".
The next release changed that to "This is release 981211 of Wine, free implementation of Windows on Unix".
As far as I've been able to tell, there were two reasons they stopped saying it was an emulator.
First, there were two ways you could use it. You could use it the original way, as a Windows emulator on Unix to run Windows binaries. But if you had the source to a Windows program you could you could compile that source on Unix and link with libraries from Wine. That would give you a real native Unix binary. In essence this was using Wine as Unix app framework.
Second most people who would be likely to use Wine had probably only ever encountered emulators before that were emulating hardware. For example there was Virtual PC from Connectix for Mac, which came out in 1997, and there were emulators on Linux for various old 8-bit systems such as NES and Apple II.
Those emulators were doing CPU emulation and that was not fast in those days. It really only worked acceptably well if you were emulating hardware that had been a couple of orders of magnitude slower than your current computer.
Continuing to say that Wine is an emulator would likely cause many people to think it must be slow too and so skip it.
No, not at all like that. One slight difference is that what you said is complete nonsense.
I'm using an accepted definition of emulation:
> emulate (transitive verb)
> 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.
This usage is pretty common, for example FreeBSD has a linux emulation layer that takes Linux syscalls and translates them into FreeBSD syscalls. WINE saying it stands for "Wine Is Not an Emulator" is irrelevant to the fact that it is blatantly is one.
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.