From the WineHQ - About Wine page:
Wine began in 1993 under the initial coordination of Bob Amstadt as a
way to support running Windows 3.1 programs on Linux. Very early on,
leadership over Wine's development passed to Alexandre Julliard, who
has managed the project ever since. Over the years, as the Windows API
and applications have evolved to take advantage of new hardware and
software, Wine has adapted to support new features, all while being
ported to other OSes, becoming more stable, and providing a better
From that it sounds like there really is no specific version of Windows that WINE is based off of.
However, if you run
wine regedit and then navigate to
and select the
you'll see a registry string titled
In my case, running Wine 1.6.2, the value for
Windows XP. Then, looking at the
CSDVersion string's value, you'll notice that it says
Service Pack 3.
Thus, your safest bet would most likely be that Wine is most similar to Windows XP (Service Pack 3).
I've discovered something else in WINE. If you install
winetricks and then open it up, then click on Select the default wineprefix:
Then click Run winecfg:
You can change the version of Windows that WINE, I guess, emulates? You can change the displayed Windows version at the very least: