Wikitude competes with the more commercially oriented service Layar and an unlaunched brand-centric AR iPhone browser from AcrossAir. Japanese AR firm Tochnidot says it will launch an app similar to Wikitude soon. Will these services become interoperable so that users of one AR browser can see the content created on the other systems? That's the key question. Augmented reality (AR) is a technology paradigm that puts layers of data on top of a user's view of the real physical world around them. After years in the labs, AR development is heating up fast this summer. Several AR apps are available for Android, and numerous companies are waiting for the next version of the iPhone OS to be released this fall with support for location-based (if not marker-based) augmented reality.

Last week, what looks like the first AR app to do so snuck into the iPhone app store. Yesterday a red hot app for road conditions in major US cities made an appearance. And now Wikitude quietly let AR bloggers know today about its new release.

Wikitude's application appears to be more user-centric than its competitors. By enabling content creators to add points of interest by simply logging in with their Google, Twitter, Yahoo or OpenID accounts, there will be a lower barrier to entry than there is for creating a Wikipedia entry for a location with proper location markup that can be viewed through other AR browsers.

Hopefully, just like with desktop and other mobile browsers, we'll be able to see all the AR content someday through any AR browser. Probably the market leader right now, Layar told us this week that interoperability is something they are big proponents of, though they haven't done any legal work in that direction yet and seemed to us most interested in their own technology becoming the agreed-upon standard.

Interoperability is a technical, business and legal challenge that's much easier said than done. That work is being done by data portability, identity and open-web advocates on the web at large, but augmented reality appears set to be the new way in which people around the world will view the web of data. We'll be watching eagerly for movement towards a single AR web that browser providers compete on by trying to offer the best user experience.