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Tuesday, October 16, 2007, 07:00 am PT (10:00 am ET)

Road to Mac OS X Leopard: iChat 4.0

Apple has taken iChat instant messaging in interesting new directions with Mac OS X 10.5 Leopard, introducing support for video effects and screen sharing. Here's a look at what's new.

This report goes to great lengths to follow the origins, history, and maturity of online messaging clients. For those readers with limited time or who are only interested in what's due in Leopard, you can skip to page 2 of this report.

iChat Origins

Sending text messages between computers is one of the oldest functions around. The Unix talk command was originally used to pass messages between user accounts on the same system, and later expanded to allow users to address users on other systems over a network like an instant alphanumeric pager.

Internet Relay Chat (below) expanded upon the idea of passing messages directly to a specific host by using a server-based protocol similar to email; chat messages are relayed through IRC servers. Once logged into an server, an IRC client could participate in group chats on various channels supported on that server or distributed across a network of affiliated IRC servers.

Leopard's iChat 4.0

AOL's Instant Messenger

In the mid 80s, a variety of online services introduced home users to networking over dial up, including the Source, CompuServe, Prodigy, GEnie, and Quantum. In 1985, Apple partnered with GE to develop a graphical online service for the Macintosh called AppleLink. GE's network access rates were prohibitively expensive, which limited use of the system only to Apple's dealerships.

As their popularity grew, the cost of accessing online services dropped, albeit slowly. Quantum had been operating a more affordable dial up service for home users of the Commodore 64 called Quantum Link. Among the features of Quantum Link were OnLine Messages (below), which allowed subscribed users to participate in real time chats with each other. Sending OLMs was a premium service that charged an extra minute rate on top of Quantum Link's access fees.

Leopard's iChat 4.0

Apple struck a partnership with Quantum in 1987 to develop a graphical, consumer-oriented service called Apple Link, Personal Edition. It was released in May 1988. However, Apple almost immediately lost interest in developing online services; by the end of 1989, Quantum took it solo and renamed it America Online. As noted in Apple and the Origins of the Web: Consumer Online Systems Before the Web, Apple briefly ran back into partnership with AOL to develop eWorld — essentially a re-branded America Online for Mac users — between 1992 and 1994.

Leopard's iChat 4.0

The new AOL popularized instant messaging and the idea of a buddy list, which indicated the online status of other users. As AOL and other online services began opening Internet gateways for email and later web traffic (above), AOL developed its presence indication system as an Internet service called the Open System for CommunicAtion in Realtime. Despite the name, OSCAR was not really open to interoperability, but rather a proprietary system; AOL limited all access to it from anything outside its own AOL IM clients, although third parties kept using reverse engineering to offer alternative replacements.

ICQ, MSN, Yahoo!

In 1998, AOL bought rival ICQ and merged the two services to login to the same OSCAR network. In 1999, Microsoft introduced its own MSN Messenger, and Yahoo! later followed with its Yahoo IM product. Unlike common email systems based on open standards, all three IM systems used their own proprietary methods for accounts, messaging, and presence indication, so users of each network couldn't directly send messages to each other or see if members on other networks were online.

AOL rebuffed Microsoft's attempts to build interoperability between the two systems, fearing that Microsoft would use its Windows monopoly to embrace, extinguish, and flatten AOL's remaining marketable product as it had done with DOS application partners with Office, Java in its partnership with Sun, and its other partnerships, as related in the article How Microsoft Got Its Office Monopoly.

Apple's iChat Instant Messaging

In 2002, Apple introduced the original iChat 1.0 (below) as an IM client for Mac OS X 10.2 Jaguar. Rather than operating its own IM network, Apple partnered with AOL, which allowed iChat to find the online status and chat with its existing AOL users. Mac users could either use an existing AOL account or sign up for a free .Mac account and use it on the AOL IM system.

Leopard's iChat 4.0

Shortly before the release of 10.3 Panther, Apple released a beta copy of iChat AV 2.0 (below), which added audio and video chat features. This new functionality was based on the Session Initiation Protocol, an open standard for Voice over IP and video conferencing. The new iChat AV 2.0 (below) was included in Panther. Early the next year in 2004, AOL included support for SIP-based video conferencing in its own AIM 5.5 PC client, allowing interoperability between users on Macs and Windows.

Leopard's iChat 4.0

When either iChat AV or AIM sets up a text chat, messages are relayed through AOL's OSCAR servers. However, when they perform video chats, OSCAR is only used to look up presence indication. Once you discover a user in your Buddy List, an audio or video chat is performed directly between the two clients, with no server intermediary.

Open Instant Messaging

SIP is the product of an Internet Engineering Task Force, and serves as the IP networking standard for video conferencing. It largely replaces H.323, the older telephony standard for video conferencing developed by the ITU, and the basis of Microsoft's now discontinued NetMeeting product.

In parallel with SIP, another open IETF standard commonly referred to as Jabber has been developed to deliver an interoperable IM networking system based on the Extensible Messaging and Presence Protocol, or XMPP.

Jabber is essentially an open alternative to proprietary IM systems such as AIM, MSN, or Yahoo IM, just as standard Internet email protocols emerged as alternatives to the proprietary messaging systems of CompuServe, AOL, and closed corporate systems. Rather than being a central system of accounts managed by a single company, anyone can set up a Jabber server, just as anyone can set up their own Internet email server. Jabber servers relay messages and presence indication across the Internet just as email servers pass messages.

Another similarity between Jabber and open email is that closed IM systems can build gateways to Jabber, allowing their messages and presence indication to be shared with clients on any network. AOL, CompuServe and other proprietary systems built gateways to Internet email in the past; the result of that portability was that they lost their subscribers to more competitive Internet service providers. AOL, MSN and Yahoo have not yet delivered open IM gateways to Jabber, but instead appear to be trying to preserve their subscriber pools.

In late 2005, Google began offering its own IM service called GoogleTalk, based upon Jabber. Shortly afterward, Google bought a 5% stake in AOL and announced that future versions of GoogleTalk would support an interoperability gateway with AOL. Those developments spooked Microsoft and Yahoo, who had just announced an interoperability gateway agreement between their proprietary systems.

Leopard's iChat 4.0

Jabber in Apple's iChat AV 3.0

In mid 2004, Apple announced that the new 3.0 version of iChat AV in Tiger would support multiple video conferencing users (above), H.264 video compression, as well as support for Jabber accounts. The new version also dropped the AOL running man logo (below) from iChat's icon.

Leopard's iChat 4.0

Released with Tiger in early 2005, iChat AV 3.0 was able to work with GoogleTalk when it arrived. Until Microsoft and Yahoo! build their own Jabber gateways, iChat users would have to either:
  • use a separate IM client designed specifically for those systems,
  • use a multipurpose chat client such as Adium that supports multiple, proprietary networks, or
  • use a server gateway that automatically logs into their accounts on proprietary systems and relays messages to them or another Jabber server.

Both Apple and Google are working to create interoperability between Jabber and SIP, which overlap in some functionality. An explosion of open VoIP audio and video messaging would be devastating to the proprietary IM vendors, but would also crack open the world's telephone, long distance and mobile phone markets, replacing everything with Internet based traffic. The existing VoIP market is currently dominated by proprietary systems such as eBay's Skype.

With open VoIP based on Jabber and SIP, companies with a natural telephone monopoly or a lock on mobile phone frequencies would be washed away and replaced by Internet infrastructure. That's pushing Google to seriously eye the available radio spectrum being auctioned off early next year.

On page 2 of 2: Leopard's iChat AV 4.0; Document Sharing; Screen Sharing; Text Chat Features; and Video Conferencing Features.