AOL is making its AIM and ICQ instant messaging services inter-operable with enterprise instant messaging (IM) systems from other vendors.

Through the Enterprise Federation Partner (EFP) program, AOL wants to make it possible for users of various enterprise IM systems to add AIM and ICQ users to their IM contact lists and vice versa, and allow them to exchange messages.

"The biggest thing about this announcement is that you're starting to see true inter-operability in the business environment. Inter-operability is one of the sticking points for the growth of instant messaging in the enterprise. Right now you have little islands of instant messaging that can't communicate with each other very well," said industry analyst Michael Osterman. "This is a major step forward because it's starting to deal with a lot of the real business grade IM systems out there and tying them together."

Along with the launch of the EFP program, AOL is announcing four partners whose enterprise IM systems will interoperate with AIM and ICQ: Antepo, Jabber, Omnipod and Parlano. Notably absent from the program so far is IBM, whose Lotus Sametime is a major enterprise IM system, which several years ago inter-operated with AIM but not anymore.

Until now, the most common way to link AIM with enterprise IM systems has been through third-party gateway software, workarounds which can be complicated to implement and sometimes yield unreliable performance.

At the heart of the interoperability problem is the variety of protocols employed by IM vendors, which makes it at worst impossible and at best difficult for their systems to work together. Until the IM market settles on one standard, the federated approach AOL is taking with this program is the next best thing in the business sector, Osterman said.

There is a growing need for interoperability among IM users, particularly in the business segment as many companies that use enterprise IM systems internally need to let their users communicate with clients and partners who use a public IM network, such as AIM. "On the business side you have a built-in incentive to provide interoperability because if IM System A can talk to IM System B then they're both more valuable," Osterman said.

"We have a lot of customers who have a requirement for accessing the AIM network for business purposes," said Paul Guerin, Jabber's CEO. Jabber plans to offer its customers this AIM connectivity in June as an optional subscription service, Guerin said.

AIM is the largest of the free, public IM networks aimed at individual users, and AOL estimates about 14 million people use it for work. The two other major public IM networks are Microsoft's MSN Messenger and Yahoo's Yahoo Messenger. These networks don't work with one another.