AOL, Sun get buddy-buddy

Sun becomes the second company--after IBM's Lotus--to undergo interoperability trials with the online giant. Its America Online division, which owns the two most popular instant messaging services, AOL Instant Messenger (AIM) and ICQ, has long been criticized by competitors for blocking efforts to communicate with its products.

Competitors have also labeled AOL as a monopolist for its market dominance in instant messaging.

Some the most vocal critics, including CMGI's iCast and Tribal Voice, have gone out of business, however. Microsoft remains the most formidable challenger to AOL and has taken steps to embed its upcoming Windows Messenger product into its forthcoming Windows XP operating system.

Since stepping up its Windows Messenger initiative, Microsoft has become less vocal about forcing AOL to open its network. Not surprisingly, AOL has complained publicly that Microsoft is up to its old ways by tying its messaging products into its Windows monopoly, creating an unfair advantage against industry leaders.

The pairing of AOL and Sun comes as no surprise. Both companies are critics and competitors of Microsoft. The companies also collaborated in the past, creating enterprise software company iPlanet, which AOL has been pulling out of.

The interoperability tests come after iPlanet's announcement Tuesday that it would create an instant messaging service for its Portal Server software. The product's Instant Collaboration Pack will support secure instant messaging between employees and their external business partners. Sun and AOL will test ways for the Instant Collaboration Pack to communicate with AIM.

"This will be a technical test of a possible interoperability protocol, similar to the test we announced with Lotus this year," AOL spokeswoman Kathy McKiernan said.