The Web, e-mail, YouTube, Facebook, Second Life, and many other applications and sites are creating a mirror world in cyberspace, like a reflection of a town in a pond’s still surface. Now people all over the world are holding their breath in anticipation of this Wednesday, May 16, when Microsoft is set to launch the beta version (a limited-release test and preview) of Halo 3 — a multiplayer, Web-based mirror world that is fascinating millions of fans around the world.

For Halo-players everywhere (myself included), this is more than a video game, and Halo fans are more than a bunch of adolescent nerds. For one thing, many adults play. More important, Halo players have built their own thriving international community. Books, movies, and other video games occasionally have large followings, but Halo is something else: a global community, part physical and part “virtual.”

The original Halo required players to be gathered in one physical location, huddled over a game console in front of a television driven by a video-game machine. When Halo 2 debuted, you could get together at a friend’s house or on the Internet. It allowed players all over the world to meet and socialize in the cybersphere. The long-awaited Halo 3 will offer new features to simplify and encourage improvised cybersphere gatherings, and make it easier to integrate such gatherings into Halo’s own mirror world.

Microsoft was the first American company in a long time to plunge into the video-game market with both feet — games and hardware to play them on. Naturally, it made a big splash. In November 2001 it released Xbox, a computer designed exclusively for wasting time — for games and entertainment. It also released a handful of Xbox games. Among them was a game first demo’ed to wild applause on the Apple Macintosh in 1999, then bought by Microsoft and finally released two years later as one of the first Xbox games. It was called “Halo: Combat Evolved.” The bizarre plot centered on a giant spinning ring with humans and space creatures running around its inner surface. Players were required to kill space creatures, who try to kill humans, and ultimately to destroy the ring before it could be used as a weapon to wipe out humanity. Moments before the ring blows, you fly away to safety.

The game sold millions of copies, and Microsoft’s Bungie Studios followed its smash hit with Halo 2 in November 2004, which also sold many millions. Why these huge sales? Halo was different from the glut of similar titles because of its robust multiplayer support, but also because it was easy for friends to improvise their own games — for example, by bumping off each other’s virtual avatars. (Your avatar is a simple digital version of yourself, dressed in armor.) Eventually, Halo’s multiplayer features developed much broader implications — some of them evoking the future of the Internet.

Soon after Halo was first released, players began to make videos of themselves accomplishing virtuoso feats, such as breaking into places in the Halo game world they were never supposed to see, or advancing through ever more difficult levels of the game at breakneck speeds. These videos of top Halo performers soon became popular. Before long the best players were celebrities in the steadily growing online Halo community. Their performances have since evolved into speed and skill competitions organized by the community itself, with no evident help from Microsoft.

In April 2003, a group of friends led by Michael Burns, a Texan in his 30s, released the first episode of “Red vs. Blue.” This is a sitcom that has since become hugely popular among Halo fans. Episodes are free at the Web site, but fans pay money for DVD versions and subscriptions. Episodes are rarely longer than five minutes. They all center on soldiers sitting in a canyon doing nothing. The soldiers are Halo “avatars” and look alike except for their uniforms. Some are red, some blue. They trade insults. Often minor skirmishes follow. The point of this neoexistentialist show is its sheer pointlessness. (Sartre would have loved it.) Neither side stands for any nation or cause, and there’s no evident reason for them to fight.

“Red vs. Blue” was created entirely in the Halo multiplayer world and distributed on the Web. It became an instant hit and is now nearing its 100th and final episode. Before long, hundreds of RvB-style videos appeared on the Web, filmed by groups of friends who lived all over the globe but had gathered at locations inside cyberspace. The most unusual new program was “This Spartan Life,” a Lettermanstyle cybersphere talk show where “guests” from the gaming industry are interviewed by the host within Halo 2’s virtual world. It even has its own group of dancing avatars to entertain the audience.

The best part of the Halo mirror world is the people you meet there. I’ve met players who turned out to be students at my own high school in Connecticut; I’ve met American soldiers deployed on the other side of the world. I’ve become good friends with a group of teenage English boys (and met one of their girlfriends, who stopped by the cybersphere to say hello). I’ve spent hours chatting about topics from music to politics. (English politics fascinates me, but not them — or not at first; by now several have become interested.) I know their names and addresses, their hobbies, colleges, and the courses they’re taking. I know that “scousers” (or “scouses”) — English slang for Liverpudlians — speak and write with a Liverpool accent. I’ve learned that the rest of the United Kingdom regards scouses as thieves. And a surprise: Plenty of British teens hate the monarchy. (One friend demonstrated the point by yelling a random obscenity about the Queen into the street and letting me hear the enthusiastic response.)

I’ve surprised them, too. They were startled to learn that Americans must cover their windows with bug screens — but this fact often surprises Europeans. They were even more startled to learn that (because I am trained and certified) I can go to a rifle range and shoot real guns whenever I want. I explained that this was known as “freedom” and referred them to the Bill of Rights.

Web-based games do many things, but creating communities is the single most important. Today we badly need replacements for the neighborhood communities we used to depend on, that are now so hard-pressed. Halo’s informal, easy-to-use mirror world might be a portent. The Web of the future might look like this.