"Applets" (small programs embedded in Web pages, written in the Java language) can automatically load quickly and then run on "virtual machines" (provided by the user's own browser no less!) to provide animation, games, chat rooms, stock tickers, etc. and now an online catalog for Harris County Public Library, all without input from the Web surfer.

Users can send personal information such as library barcode numbers over the Web to place holds on books they want to read or see if previous holds have been filled yet, all from the convenience of their home computer!

Java was developed by Sun Microsystems and debuted in 1995. Current Web browsers (such as Netscape Communicator and Microsoft Internet Explorer) include Java plug-ins as a standard feature and thus come ready to work with Java.

Even better, Java applets don't care if the original program was written on a PC and the Web surfer's computer is a Macintosh or a Unix computer (or vice versa). Until Java came along, programs had to be written for specific kinds of computers (called platforms). If your computer's operating system was "incompatible" with the program, you were simply out of luck.

One minor drawback to using a "software" computer, however, is that, since the Java applet is "not really there" (because it runs independently of both the browser and the operating system), you can't just hit the usual browser buttons, such as the print icon. For example, when using the Java version of the HCPL catalog, if you find you really want to print out something, end your Java session and just search using WebPAC. WebPAC just uses regular HTML and all of your browser buttons work fine with this.

On the other hand, a "not really there" Java applet won't ever infect a Web surfer's computer with computer viruses or otherwise damage the surfer's machine. So it's harmless as well as being quite useful!

So what else is Java used for besides library catalogs? Online shopping, online banking, online weather, and lots more!