In spite of the hard-core technical and Internet-centric ethos typically associated with the Linux community, the open-source OS isn’t known for having particularly good instant messaging clients.

That could be changing, however. As Linux is steadily winning favor in the workplace, a crowd of up-and-coming third-party IM clients are growing in popularity — some of which sport features that users of other OSes ought to envy.

Here, then, is a rundown of the most popular IM clients for Linux. Most of these applications are for Gnome or KDE, and typically are supported by the most common Linux distributions.

Jacks-of-all-protocols

The undisputed king of Linux instant messaging clients is gaim. While the app originally supported only AIM’s TOC protocol, it ultimately evolved into supporting OSCAR, as well as a staggering multitude of other protocols. Similar to Windows offerings like Cerulean Studios’ Trillian, gaim also supports Yahoo!, MSN Messenger and ICQ. But it doesn’t stop there: gaim also supports Jabber, Gadu-Gadu, Zephyr, and the Napster IM protocols. And like Trillian, it can handle multiple simultaneous accounts on the services.

The interface is clean and borrows the familiar icons from each service to demarcate the original networks of each contacts. Additional improvements over the networks’ clients include logging and client-side Buddy List hosting.

The open-source, GTK2-based gaim also is built with extensibility in mind. A plug-ins system provides for additional features, like a spell-checker and the ability to add chat rooms to a buddy list.

The app doesn’t support file transfer under OSCAR, but it does under TOC. Other minor quibbles: the application doesn’t support “docking,” and occasionally, cryptic error messages pop up without explanation.

Gaim is the leader in the space, but it’s not the only Linux IM client offering multiple protocols and sporting a sizable following. Formerly known as EveryBuddy, AYTTM (stands for “Are You Talking To Me?”) is another open-source, multi-protocol IM client on the move.

AYTTM supports AIM TOC, ICQ, Yahoo!, IRC, MSN, and Jabber, and is intended to be able to support any new protocols that come along. (Nevertheless, the developers concede that support for AIM’s more robust OSCAR protocol is unlikely to come anytime soon, since they simply don’t use it enough to warrant devoting significant time to it.)

Support for the protocols it does currently offer isn’t uniform, however. Group chat is supported with AIM, MSN, Yahoo! and Jabber, while file transfer is implemented fully with Yahoo! and MSN users, but AYTTM users cannot send files to AIM users.

Still, AYTTM has a lot going in its favor. Unlike most multi-protocol clients, AYTTM attempts to merge Buddies and contacts from each system into groups sharing members from each network.

AYTTM also offers a number of thoughtful improvements over the networks’ IM clients: smiley “themes,” logging, tabbed chat, automatic Babelfish translation, and spell-checking. It also supports limited integration with gnomemeeting, a videoconferencing application much like Windows NetMeeting, for GNOME.

Less popular, but steadily improving: the networks’ clients

On Windows systems, it’s often a tough sell to encourage consumers to choose a third-party client over am IM network’s own offering — since third-party clients tend to lack important, popular features found in AIM, Yahoo! Messenger or MSN Messenger. But that hasn’t been the case in the Linux realm.

Version 1.4.286 of AOL’s Linux AIM client offers a number of important enhancements over its previous iteration, adding file transfer, improved performance of pop-up messages, support for @mac.com addresses (and one would assume, other private-label domains, in support of AIM’s push for enterprise customers), and an icon indicating when Buddies are wireless, and making installation easier.

Still, the improvements don’t do much more than bring Linux AIM barely up to the level of its third-party rivals. It doesn’t support direct-connect, voice messaging, IM forwarding or SMS messaging, or Buddy Icons. Also missing are the stock/news ticker, dimmed “idle” buddies and idle messages, mail integration, Search for a Buddy, and Send Buddy List support.

In short, the AIM Linux client offers IM features on par with the rest of the pack — a state of affairs that improved dramatically when file transfers were added in April. Prior to that, the application seemed unstable and severely underpowered.

Yahoo! has done far better with its own instant messaging client for Linux. Indeed, the company’s Yahoo! Messenger for Linux has, in its latest version, been made to actually resemble its more popular Windows version. It also now supports the ability to enter contact information and nicknames for Yahoo! users on other OSes.

Yahoo! Messenger for Linux also now supports the same sorts of content panels that the Windows version offers, with tabs for Finance, News, Sports, Weather, and so on. Typing notifications and overall speed and stability improvements round out the package.

Lean and mean: the specialists

If Linux AIM needs a model to pattern itself after, it might consider looking to both Yahoo! Messenger for Linux and Kinkatta, a KDE-based AIM client that’s slick-looking and sports a solid feature set.

Kinkatta’s most distinctive feature is how closely it feels to the Windows AIM client. The interface’s layout and color scheme is clearly different, but it supports almost all of the common Windows AIM formatting and messaging capabilities, barring voice chat and direct transfer.

Improving on the original AIM, Kinkatta offers Buddy Pounce, IM logging, chat room support, printing from the chat window, and customization of the toolbar and the chat window’s colors.

Another IM client with heavy extensibility is TiK, the successor to America Online’s short-lived Tck/Tk 8.0 client released in 1999. As such, TiK only supports the AIM TOC protocol. But a bevy of add-ons provide support for IM logging, remote PC administration and “Buddy Pounce” — queuing an IM for delivery as soon as a Buddy becomes available. Tik also enables users to reconfigure their interface’s colors and window sizes, offering a level of customizability some degrees shy of true skinning, but far ahead of rivals.

Yet while it sports a multitude of features, TiK lacks some of the features found on Windows AIM. For instance, there’s no support for Buddy icons.

In addition to TiK, there are a number of other popular TCL/Tk-based clients. Notable among the rest is Alvaro’s Messenger — a modified, multi-language version of the now defunct Compu’s MSN Messenger. With the exception of images of Tux, the Linux penguin, scattered throughout, Alvaro’s Messenger, or aMSN, as it’s known, presents an interface nearly identical to MSN Messenger (prior to version 5) — aping icons, font styles and graphics. It even supports animated pop-up windows, indicating when other users sign on or log off, in the style of MSN Messenger.

aMSN also supports a number of high-level MSN Messenger features, like mailbox integration and nickname changes, and improves on the original formula with logging and docking. More than 30 languages also are supported.

Tkabber is a TCL/Tk-based Jabber client, supporting a number of cutting-edge Jabber technologies.

The app offers spell-checking, encryption, emoticons, file-transfers, vCards, some customizability in interface, multi-language support, Jabber Browsing, and Jabber avatars. Non-tech-savvy users be warned, however: binaries currently are only available for Debian distributions.

LICQ is probably the most popular pure ICQ client available for Linux. In addition to the standard ICQ features — including SMS integration — LICQ offers Buddy List organization, network monitoring window, themes and a customizable UI, remote access to a locally running ICQ session, per-user customized auto-responses, SSL client-to-client connections, and a plug-in system for added extensibility. Limited support is available for e-mail integration.

The major Linux IM clients have several benefits that their Windows brethren lack. For one thing, since the Linux user base is fairly small and trending toward the technical rather than mainstream consumer, IM clients making unauthorized use of proprietary protocols (like OSCAR) or user interface elements (as with aMSN) are more likely to escape the wrath of the IM networks. Indeed, crackdowns by the public networks are far rarer in the non-Windows worlds.

And just as important, Linux IM clients are typically open-source — and supported by a rabid fan base. As a result, the clients are developing rapidly, despite having little in the way of full-time programming staffs, and fixes and updates are frequent. For instance, look for another version of AYTTM due out at the end of the month.

So, as advocates for Linux push for a greater role for the OS in the back office and on the desktop, it might be prudent to keep an eye on these emerging stars — they might be the IM clients we’re using tomorrow.