I finally figured out how to run a webserver from my computer.  I used EasyPHP and got help in setting things up from lineman.net.  The reason why this is significant is because now I can run PHP and other related things from my own computer.  Ever since I started using PHP and WordPress, I've had to test new things directly on my website.  Now I can try them out before I implement them.  This obviously wasn't a problem with plain text HTML, which automatically opens in any browser.