Surprisingly, for a company that usually brings a novel twist to an old concept whenever it launches a product, Google Talk is years behind rivals such as Yahoo! Messenger, Windows Messenger and AOL Instant Messenger, in terms of features.

There is no group chat, no file transfer, no videoconferencing and not many opportunities for customization. There’s also no search. On the upside, the interface is not as cluttered with useless junk and advertising as some competing products.

But it’s what’s under the hood that may prove to most interesting, longer term. The company is making a show of supporting standard protocols from launch, and is actively pursuing the elusive IM users’ dream of cross-network interoperability.

One key question Google is asking itself is, according to director of product management Georges Harik, How do we stop the Balkanization of the instant messaging world, which we think is a pretty big barrier?

What Google has done is support XMPP, an Internet Engineering Task Force standard for presence and messaging that was pioneered by Jabber and the Jabber Software Foundation in 1999.

This means that third-party IM clients that support XMPP should theoretically be able to connect to Google Talk. It does not yet mean that other XMPP/Jabber servers can talk to Google’s service, but the company is working on that.

From everything I’ve seen so far they’ve followed the spec quite well, so others who have implemented the protocol should be able to connect, and I expect that would be the case going forward, Jabber Foundation executive director Peter Saint-Andre said.

Google said that it is already in the process of federating its new service with other providers of IM and VoIP services. The first two to be named are EarthLink’s Vling and SIPphone’s Gizmo Project.

Both of these services use SIP, the IETF standard Session Initiation Protocol, to set up and manage VoIP calls. A SIP extension, SIMPLE, handles text-based messaging and presence.

We’re as ready to support SIMPLE as were are XMPP. We’re not really hung up on protocols, Mr Harik said. We’re going to try to interoperate with SIP.

EarthLink’s director of voice Tom Hsieh said: They are building a SIP gateway to interoperate with our voice over IP services, and we are building a gateway to translate SIP into XMPP for their instant messaging services.

For years, IM users have been crying out for the ability to chat with all of their colleagues and friends using a single client, no matter which IM networks they are connected to.

The most significant development in this space was about 13 months ago, when Microsoft licensed technology from AOL that would allow its Live Communications Server 2005 users to interconnect to the AOL Instant Messenger network.

Mr Harik said Google would not go this route. The company can afford to offer interoperability without charging for it, he indicated.

In fact, Google is not talking much about business model ideas yet. The most obvious route would be to upgrade the VoIP component to do PC-to-phone voice, and then charge for long-distance calls that hand off to the PSTN.

It seems pretty reasonable to do that, Mr Harik said. I don’t think we’re against charging users. Any revenue-generating services would be those where the prices are close to our costs, he said.

Google is not about to start charging users twenty bucks to download a bunch of animated IM smileys or emoticons, he said. We’re not going to put advertising in the main window, he added.

Whether Google can act as a catalyst for full email-style interoperability is far from a slam-dunk. The sticking point in the past has always been the fact that smaller operators want to interoperate with larger players, but the larger network has no incentive.

Getting a critical mass user base is possibly the answer to this conundrum. Even if Google cannot do it alone, kick-starting federation/interoperability efforts with the likes of EarthLink and SIPphone will surely help.

While federating IM servers is possible, security has always been a concern. Spam and worms spread via IM just like email, so there has been caution.

You need a well-thought out, deliberate approach to server federation, the Jabber Foundation’s Mr Saint-Andre said. In email, we had this willy-nilly federation and we’ve seen the consequences of that.

It was said that IM, unlike email, may require contracts in place between IM network operators. Google’s Mr Harik said that may not be the case. There’s the possibility that Talk may end up leveraging the existing DNS-based public Jabber network, he said.

The company was relatively quiet on plans to upgrade the software with new features or integrate it with other Google services, due to the usual corporate reluctance to preannounce and Google’s own purported develop-first monetize-later attitude.

Maybe we could have it search for people, at a later date, Mr Harik said. Maybe we can store voicemail in Gmail, that maybe a pretty reasonable thing to do, or we could record a conversation and post it to Blogger, that may be pretty reasonable.