I've loved science fiction since I was a little kid. I grew up in the 1970s and have many fond memories of stories and films that featured technologies that today we consider mundane. One technology that hasn't quite reached that status, though, is ubiquitous personal communications. On a typical day, I use a computer (for email, Voice over IP--VoIP, and three different Instant Messaging--IM--services), cell phone (email and voice), and landline phone (voice). Each of these devices has its own operational mode and capabilities, as do the services I use on the devices. I often think how great it would be to have a single, high-function client that condensed these communications modes into one.

Microsoft apparently thinks so, too. With Tuesday's launch of Microsoft Office Communicator 2005 (formerly code-named Istanbul), the company is making a play to offer a unified communications experience that ties together call control, IM, presence, and telephony. The benefits of this unification are obvious to anyone who's ever missed an important phone call from someone who didn't have the right cell phone number or who's struggled to get VoIP softphone software working properly. Some of Communicator 2005's features are pretty cool:
- You can make phone calls to and receive them from users in your organization using either a compatible PBX system (Microsoft says it's hooked up with major PBX vendors including Avaya, Cisco, and Lucent) or your computer. With compatible gateway software, you can also make computer-to-telephone calls.
- Presence information is much richer than that in today's IM clients. Communicator 2005 lets you see your contacts' free/busy data (which comes, naturally enough, from Exchange), and you can set up custom presence messages that work like the Outlook/Exchange Out of Office message model. In fact, if you set up an Out of Office message with Outlook or Outlook Web Access (OWA), your IM contacts will see it. This capability is extremely useful because traditional IM presence data indicates only that a contact is offline.
- You can initiate calls from within Office applications and from Microsoft SharePoint Portal Server sites. - You can search the Global Address List (GAL) to find people. If you've used Microsoft Office Live Communications Server with Windows Messenger, you're probably used to the annoying requirement of having to know your correspondents' email addresses before you can add them to your contact list, but no more.

Communicator 2005 depends on and was announced in conjunction with Live Communications Server 2005 Service Pack 1 (SP1). SP1 includes some welcome new features, including the ability to restrict spam over IM, a better interface for setting up federated connections among organizations, and support for public IM connectivity with AOL Instant Messenger (AIM), MSN Messenger, and Yahoo! Messenger users. PIC support comes from a separately licensed component that you don't have to buy unless you actually need it.

What does this all have to do with Exchange? Apart from the obvious (like the use of Exchange free/busy data in the Communicator 2005 client), you might remember Microsoft's announcement that Exchange 12 will support unified messaging. The Live Communications Server 2005 launch indicates that Microsoft plans to use its Session Initiation Protocol (SIP) capabilities and PBX connectivity as the backbone of its telephony integration strategy. The Exchange announcement tells us something about the capabilities Exchange 12 will probably have (i.e., the ability to store and originate voice mail messages and make them available to clients). With the advent of Communicator 2005, we now know something about what the client interface to this functionality might look like and how it will work when the pieces are all available.