Stupid question about plug-ins and standards.

[Modeler]

Forgive my ignorance (the most complex piece of code I ever wrote had the line "20 GOTO 10" in it) but I have a question about the standards for audio plugins:

If for example the standard is VST, why is it then O/S specific i.e. VST/Windows? I can understand that VST/Mac OS would be different as they are compiled for different CPU achitecture. Why then, are they not classified as VST/x86 etc? What got me thinking about this is let us imagine that on a cold day in Hell, as Satan ice-skates to work Image-Line decided to port FL Studio to Linux. None of my VSTs would work as they're Windows-specific right?

So if VST is an open standard and the application makes calls to the plugin via an API, why should the O/S matter?

Thanks in advance to the knowledgable soul who steps forward and exposes me for the primitive chimp-like life form I am.

[kara]

I could be wrong here, but.... I tought that most native VST's are based on the Steinberg Vsti SDK, which is windows only.
Others are made with SE wich create only Windows Vst's.

Rony