You've got your high-speed Internet connection, you've wired the house with high-speed cable, and you've installed, or are seriously contemplating, a wireless LAN. What's next? The answer is simple: you set up a home server.

If you work at a company with a network, you're familiar with the concept. A corporate server is a company's heart and soul: it's the e-mail hub and repository of important documents. It is where companies keep their crown jewels.

Unfortunately, the corporate server requires a substantial support staff. It's the computer that renders every desktop unusable when it crashes, and it's the ultimate target of hacker attacks. With all of these problems, why would any sane person want to have one at home?

Well, I've had a server in my basement since 1995, and frankly, I wouldn't want to live without it. Always running, my server holds my personal files, my music collection, and all of the digital data that I've been building up over the past 20 years. The server also mirrors the data that's on my two laptops and my two computers at MIT, keeping everything properly synchronized, and it automatically backs itself up. I can also log in remotely and get an important file if I happen to be at a friend's house. It's easy to lose your data if you keep it on a single computer. My server gives me automatic redundancy-and that safety net has saved me from many data disasters.

The server secures my data in another way, too: it's bolted into a rack, and that rack is bolted onto the floor. I've heard too many stories of people who have had computers stolen and lost all the data they contained. If my house is burglarized, it's unlikely that the thief will take the time to unbolt that box in the basement.

Of course, there's more to a home server than shared files and folders. The word "server" actually has an ambiguous meaning here: it refers both to the computer itself and to the programs that provide service to other machines. For each different service, the machine runs another program. The machine in my basement runs dozens, which means it is providing a range of services far beyond storing my data.