Partscounterman: Linux is an "open source" operating system. Open source means that the source code, i.e. the raw material from which the system is compiled, is published widely on the web. You can download the source code from a canonical (standards-bearing) web site, and compile it into object code on your own machine; similar to buying seeds and growing your own vegetables in your own garden.
The fact that the source code is public, means that anyone with appropriate skills can contribute to it, which is how its functionality evolves over time. Also, the public nature of this makes it easy to conduct peer review, i.e. for others to critique it and fix problems before they get out of hand.
Also, since it's public, people can more easily write applications (software that does specific tasks, such as word processing, calendar, video production, etc.), than they can for a "proprietary" operating system, where the maker gives them "only so much information", i.e. enough to let them develop applications, but not the whole thing. The difference is, if you have the whole thing, you can optimize your applications in ways that aren't otherwise possible; make it run faster, make it more secure, etc.
And speaking of security, it's far more secure than Windows, because the peer review process continually improves security, and because you have total control over what is and isn't allowed to occur on your machine. Whereas with Windows, you have to depend on Microsoft's capacity to deal with security issues, and recent history shows that Microsoft can't keep up with the number of attacks and other problems that occur.
In fact, Linux has become the gold standard for high-security government systems. The National Security Agency (NSA), whose mission includes making and breaking codes, and which handles the most sensitive military secrets, has developed a version of Linux called Linux SE (we call it "NSA Linux"). As of at least middle of last year, you could go to
www.nsa.gov and download the source code, and use it on your own machine, free of charge. Since the source code was public, the community-at-large was able to vouch for the fact that NSA wasn't hiding any of its own spyware in there. So, for example, security-conscious IT managers in companies that depend on protecting their information, could use NSA Linux and meet the most stringent of corporate due-diligence standards.
With all this, it's astounding (and frankly obscene) that the voting machine infrastructure has not been built on open-source platforms. The entire inner-workings of such a voting system could be available for public examination (i.e. by any reasonably smart geek, who in turn could be hired by e.g. the League of Women Voters or other civic groups). Detailed explanation omitted to save space, but the bottom line is that this could restore credibility to our election system.
In addition to Linux, other open-source operating systems include FreeBSD and OpenBSD. BSD is also the foundation of Macintosh OSX, which gives OSX considerable advantages in terms of security, speed, and flexibility. (I'm using it on the machine I'm writing this on.)
If you have an older PC that is too slow to run the current version of Windows, it's worth experimenting with Linux and the BSDs. You'll find they run as fast on an older machine as Windows does on a newer one, and you'll be amazed at how it feels to be free of security and reliability problems, and to be able to do darn near anything you want at cost zero. However, for non-technical folks it can be somewhat challenging to set up, so find a local geek who's willing to help get you up & running.