I would like to backup my MiniDV tapes using the FireWire port in a raw format (byte for byte) to avoid any degradation in quality.
What (preferably open source) software would you recommend for Vista Basic?
Also, is there a standard file format?
If your camera and PC both have a FireWire (a.k.a IEEE-1394, Sony i.Link) port, you should be set. Hook your camera up to your PC, load a tape, and fire up the free WinDV to capture the video.
I don't have the time at the moment to get into particulars, but some basics:
Tape is actually a very stable storage medium. Keeping the original MiniDVs on a shelf, plus a spare player (preferably with a FireWire output) is a solid backup strategy.
DVD-Rs suffer from bit rot even in the "archival" quality discs -- it's a technology issue. And hard drives, while fairly stable if they're not left connected to a machine but instead shelved, are delicate in comparison to tape. You could look in to solid state drives but the cost per byte there is quite high. Long term data archival is usually done to tape at the corporate level: it's cost-per-byte is very good and the durability goes from respectable to very good if you can store them in a well-controlled environment.
So, my answer is: don't bother. Put the tapes in a box and keep a spare player around.