How All-in-one Instant Messenger Works

An Internet user on Tencent QQ.
A Chinese Internet user accesses the Tencent QQ instant messaging client on Sept. 3, 2008. Many all-in-one instant messengers can run popular chat services from all over the world. See more computer pictures.
AP Photo/Zhou Junxiang/Imagechina

Ever since people began communicating over computer networks, they've found faster and more convenient ways to keep in touch. Instant messengers provide this speed and convenience, whether you're on a private network or on the Internet. The convenience is limited, though, when your friends are all on different instant messenger services.

In the early 1990s, the typical commercial online service provider required you to install its proprietary client application on your computer if you wanted to connect to its service. Popular companies like America Online (AOL) each developed their own instant message protocols that worked only with their client software. If you wanted to send messages on a particular service, you had to use that company's client software.


Even today, that's still mostly the case. What if you're using AOL Instant Messenger (AIM), but you want to keep in touch with friends on Yahoo or MSN? Should you install the application for each protocol, or should you try to talk your friends into AIM instead?

There's an option that lets you stay connected to everyone without installing individual clients on your computer: Use an all-in-one instant messenger. These programs can connect to several instant message protocols at one time. Plus, they often have features to merge, organize and customize all your instant messenger contacts.

This article explains why you might use all-in-one messengers, describes the technology behind the software and profiles the different applications you can choose from.


All-in-one Instant Messenger Explained

Pidgin IM client
Use the Accounts window in Pidgin to add, edit and remove accounts, and to enable or disable an account.
Screenshot by Stephanie Crawford

Thanks to the popularity of instant messaging, you can find a variety of all-in-one instant messengers to choose from. Each offers different features and functions that are similar to proprietary instant messenger clients like AOL Instant Messenger (AIM) or Yahoo Messenger. Many all-in-one messengers are available for free, though some include advertisements unless you pay a fee.

In an all-in-one instant messenger, you can connect to each instant message service by adding accounts. An account in the messenger configuration includes the necessary information to connect to one instant message service using an existing profile for that service. User interface menus like "Accounts" or "Connections" let you manage your profiles, including controlling which accounts should connect when you start the application.


Each all-in-one messenger connects to a select group of services using their instant message protocols. The protocol is the set of networking rules that allow you to exchange data on a certain instant message service. Some protocols are used by multiple services, such the OSCAR protocol used by AIM and ICQ.

All-in-one instant messengers are available for both computers and smartphones. Some messengers have a wizard when you first open them that prompts you to add one or more accounts. When you've installed and set up your new all-in-one messenger, browse the interface and documentation to learn more about all its features.

Web-based instant messengers like Meebo give you the freedom to go anywhere. Instead of installing an application onto each computer, you can create an account to use the Web application and access it from any Web browser. You can add and manage accounts in the Web application, and you can instantly connect to those accounts each time you log in to the Web site. Features for Web-based messengers may be more limited that those you'd install on your computer, but you might prefer the mobility.

Go on to the next page to read about the technology behind these all-in-one instant messengers.


All-in-one Instant Messenger Technology

Each instant messaging service uses a protocol that defines how your client should authenticate with service's servers, and how it should exchange information between clients. All-in-one instant messengers can connect to two or more of these protocols using a single user interface. Plus, they can often manage multiple connections to each protocol.

The technology in an all-in-one instant messenger controls both your user interface and your connections to each instant message protocol. Each one includes some way to keep track of the profiles you add, such as saving this information in a user profile or configuration file on your computer. Besides maintaining this and other common features, developers for all-in-one instant messengers have to decide how to keep up with the latest updates to each protocol.


So what does the all-in-one instant messenger need to know to use each protocol? First, it needs to know the data types that the protocol handles, and how the service expects that data to be encoded. Second, it needs to know how to recognize a packet associated with that protocol, which involves frame types and headers used in TCP/IP networks. Finally, it needs to know the application programming interface (API) that directs the server and clients for that protocol.

Some businesses behind some proprietary instant message protocols have tried to limit use of those protocols to their own client applications. They have refused to publish the data type, packet or API information about their protocols. However, enthusiastic developers have found ways to capture each protocol's packets from network traffic, study the data, and reverse-engineer the protocol. With this information, they've added each protocol in their own instant message clients.

With growth in the open source movement, some companies have opened up the API for their instant message protocols, making it easier for them to keep up with ongoing changes. For example, AOL opened its OSCAR protocol as part of its Open AIM 2.0 Developer Program in March 2008 [source: AOL]. OSCAR is the protocol currently used by AOL Instant Messenger (AIM) and ICQ.

Even if an all-in-one instant messenger connects to a protocol, application developers have a choice of whether to implement all the features of that protocol. For example, all-in-one messenger Pidgin connects to AIM, Yahoo! Messenger, GoogleTalk and other protocols that include video chat in their native clients, but its version 2.6 only implements video chat in the GoogleTalk protocol.


All-in-one Instant Messenger Providers

Trillian home page
Trillian's home page lets you download the Windows client, visit the Apple App Store for the iPhone version or log in to chat on the Web.
Screenshot by

There are many different all-in-one instant messengers out there, most available for free. The following are some things you might to consider when choosing which all-in-one messenger you want:

  • Is there a version for my computer?
  • Does it connect to all the instant message services I want to use?
  • Does it have the features I use for each protocol (like video chat or voice messages)?
  • Is the interface too complicated? Too simple? Not intuitive enough?
  • Can I connect to multiple accounts on the same service?
  • Is it okay for me to install this on my computer at school? At work?
  • If other people are using the same computer, is my account information safe?

Here's a list of some popular all-in-one instant messengers along with some of what makes them unique:


Trillian has been around since 2000, and its user interface and features have evolved a lot through the years. Trillian has been available for Windows since its launch. It's now available as a Web application at and an iPhone application from the iPhone App Store. A Mac OS X edition is currently in development. Cerulean Studios, the group behind Trillian, boasts that its newest release, Trillian Astra, has more than 400 features that include instant messaging, social networking, and video and voice calls.

Pidgin is one of several all-in-ones that use libpurple, a C library that takes care of all the different protocols behind the scenes so developers can just focus on the user interface. Pidgin started as an application called Gaim, developed in the late 1990s as a way to use AOL Instant Messenger on Linux [source: Herper]. It's still free, open-source software, and is now available for Windows and for several popular Linux distributions.

Adium and Proteus are all-in-ones for Mac OS X that use the libpurple C library like Pidgin. They support Growl notifications, so you can read each new message alongside other notifications when they pop up in the corner of your screen.

Digsby has a playful look and a built-in notification system. You can personalize Digsby with application skins and conversation themes. The latest release of Digsby is only for Windows, but the Digsby Web site promises future releases for Mac or Linux.

Meebo is a Web application that lets you enjoy all the features of an all-in-one instant messenger without downloading and installing any new software. Plus, Meebo lets you sign in from anywhere, instantly connecting you to all your services with only one username and password.

IM+ and BeejiveIM are mobile phone applications that let you take the all-in-one features anywhere you go.


Pros and Cons of All-in-one AIM

All-in-one instant messengers are a convenient way to connect to friends on different instant messenger services. Does that convenience come at a price? Here are some of the pros and cons of these applications.



  • You don't have to use multiple clients, each with different features and functions.
  • You can free up your computer resources by running one instant messaging application instead of several.
  • You can view all your instant messaging contacts into one list.
  • Depending on which application you're using, you can also use it to connect to IRC channels, social networking systems, and voice and video services.


  • You might find the list of protocols confusing and you might not be sure what to do with the ones you don't recognize.
  • You might find the user interface cluttered if there are more features in it than you intend to use.
  • You might find the user interface confusing if it has features you're not familiar with.
  • You might lose some protocol-specific features you like from the proprietary clients, such as webcam sharing or animated avatars.
  • Without different user interfaces to distinguish between services, you could accidentally send an embarrassing personal message to a professional contact.
  • The application might have better support for some protocols than for others.
  • Like with some proprietary clients, you may have to pay a fee if you want to avoid advertisements.

For links to lots more information about instant messengers, aim your Web browser at the next page.


Lots More Information

Related HowStuffWorks Articles

  • AOL. "AOL Announces Open AIM 2.0 Developer Program." AOL LLC. March 5, 2008. (Dec. 18, 2009)
  • AOL Developer Network. "OSCAR Protocol." AOL LLC. (Dec. 18, 2009)
  • Herper, Matthew. "Better Instant Messaging Through Linux.", Inc. July 16, 2002. (Dec. 19, 2009)
  • Internetnews Staff. "AOL Buys Israel's Mirabilis." June 8, 1998 (Dec. 19, 2009)
  • Moore, Cathleen. "Messaging worlds on course to merge: XMPP, SIMPLE groups discuss interoperability." InfoWorld. Oct. 24, 2003. (Dec. 19, 2009)
  • Morris, Scott M. "GAIM: Cool and Advanced Features." Novell Cool Solutions. Nov. 2, 2005. (Dec. 18, 2009)
  • Pidgin. "What is libpurple?" (Dec. 19, 2009)
  • XMPP Standards Foundation (XSF). "XMPP Standards Foundation." (Dec. 19, 2009)
  • XMPP Standards Foundation (XSF). "XSF Sponsors: Google." (Dec. 19, 2009)