The US Internal Revenue Service is spending good money after bad on that other OS. “According to the IRS, it has approximately 110,000 Windows-powered desktops and notebooks. Of those, 52,000, or about 47%, have been upgraded to Windows 7. The remainder continue to run the aged, now retired, XP.” If it ever was a good idea to have used XP in the first place (BSODS, re-re-reboots, waves of malware…) it certainly isn’t in the best interests of the taxpayers of USA to take another step on the Wintel treadmill ensuring an infinite future sum of payments far above market cost (GNU/Linux: $0 per copy and $0 to upgrade each copy, forever). What are they thinking? That no one was ever fired for choosing M$? That M$ is essential to get PCs to do what PCs are capable of doing? Wrong on all counts.
To find multiple sources of better and cheaper software, check out the more popular distributions of Free Software on Distrowatch.com. I recommend Debian GNU/Linux for general desktop and server computing.