Vx,
Yes - not very - and no.
Linux is a viable operating system, usually instead of NT4. It is UNIX based, requiring programmes designed for such systems.
It is also 'open-sourced' - i.e. you can get the code, and as such many firms produce their own version (or 'distribution' e.g. Red Hat, Mandrake, Susie, Corel etc.), provided it meets certain criteria.
It is not as easy to use as Windows: some distibutions are command-line based, others are more Windows-like. It's basically free, which means it's on the cards to take places like Asia by storm, and knock out Windows (maybe that helped Bill Gates quit!)
Many people have horrendous set-up problems initially, because you want to keep Windows in case Linux goes haywire. Then you are in to doube-booting, with Linux defaulting the master boot record. And then if you re-install Windows because IT glitched, the mbr is overwritten and you can't get in to Linux...
Search on 'Linux' for various web sites connected with it, and also try askme.com for all sorts of help.
At the end of the day, I found it interesting to look at it and experiment a little, but it sure isn't straight forward (yet).
If you're going to try it, use a buckshee machine that you can trash with impunity!
Have fun.
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When I was on motor patrol...