1. For licensing information you should look at the
VISA Licensing page.
2. NI-VISA for Linux supports interrupts, and more importantly it
supports everything that NI-VISA for Windows supports except for
IEEE-1394.
3. I'm not really sure what you are asking here. NI-VISA
provides an easy method to communicate over several types of
buses. Some of these buses include GPIB, serial, VXI, PXI, PCI,
USB, and TCPIP. As an example NI-VISA can be used to perform
register level programming on any (NI, or 3rd party) PCI device,
allowing you to create a PCI driver with NI-VISA. So I guess to
answer your question you could use NI-VISA with nearly all of NI's
products (though many already have Linux drivers).
Shawn B.
National Instruments
