1. Skype

Skype has been around for some time and has gained momentum as one of the great tolls to call a land line from a PC. With the recently released Skype 2.0 for Linux, they have added video chat support to one of the most successfull community based software.

Unlike SIP phones, Skype is properitery and uses a P2P connection to talk and do Video Chat. Some crictisisms have arose on Skype, calling it resource and bandwidth hungry, but skype continues to have a grand following and is nowhere ceasing. Video Chat has been the most requested feature for skype on the GNU/Linux platform.

The new Skype requires Qt 4.2.1, a video card driver with Xv support and D-Bus 1.0. Most of them are available in the default repositories, so installing them is a breeze. Skype support almost all webcams and the application works great.

2. Ekiga

Ekiga was formerly known as GnomeMeeting. It is a free and open source VoIP and Video Conferencing  application meant for the GNOME Environment for GNU/Linux. Ekiga supports the H.323 and SIP protocols. Moreover, it can handle multiple accounts at the same time.

H.323 has been known to cause troubles with firewalls. The alternative to avoid problems with Network Address Translation(NAT) maybe is to use the STUN server. Still, STUN can cause problems with a severly firewalled environment. Ekiga can still be used through a separate H.323 or SIP Proxy.

When Ekiga is launched for the first time, you are presented with some questions with the help of which it configures. The user is then guided into the main window. The user can make outgoing calls or configure behaviour while accepting incoming calls.

The true strength of Ekiga lies in the fact that it supports Video Conferencing. Setting up a video device is childs play for Ekiga, provided, the device is supported by Video4Linux drivers. PArticipation in conferences is also possible through use of an Multipoint Control Unit(MCU)

3. Kopete

Kopete is the default cha t client for KDE. It has been around for a long time, but recently the development seems to have stagnated. But, still, Kopete is a great application for Linux Video Chat and does the job flawlessly.

Like its GTK counterpart, Pidgin, Kopete allows you to connect to multiple accounts simultaneously and do chats and contacts with them. Kopete shines in Video Support and has been found to work flawlessly, provided, the webcam you own has all drivers and is supported enough.

Kopete is well integrated with the KDE. Long time users of KDE will have made Kopete the client of their choice as it integrates with KMail, Kalendar etc. Kopete supports the IRC protocol as well, but not as much as XChat.

4. Gyachi

Gyachi is an improved version of GyachE, the Yahoo Client for the GNU/Linux Platform. Gyachi is a feature rich yahoo client for the free and open source community. It supports the newly changed protocols and does almost all the things that Yahoo client doeson Windows.

Gyachi supports voice chat, video chat, faders, nickname, audibles, avatars, almost all features that you find on a Windows Yahoo Client. Yet, the application remains light weight and is very resource friendly. Gyachi uses Gtk-2 as the user interface.

On the video side, Gyachi introduces a lot of improvements over the original GyachE. It includes support for far more webcams, and offers resizing of webcam pictures. Gyachi is under active development. Although Gyachi is not the all in one chatting platform, it effectively and efficiently mimics the yahoo client and does video chatting well.

5. Empathy

Empathy is the next candidate to become the default IM client for GNOME and is being seen as the most actively developed application software. Empathy uses the same library as Pidgin for communication, but it brings about a variety of changes to the user experience.

One of the major change is the inclusion of video chat.This has been missing in Pidgin. Although Video chat now supports GTalk/Jabber, work is being done to support other protocols as well. Empathy is a great IM client to use. The only limitation may be the practically absent documentation or support. The website is not even too resource high.

Empathy is dead easy to configure following the path of Pidgin. IT can add multiple accounts and touts all features that Pidgin talked off. It supports tabbed IMs and voice chat. Another addition is the ability to add SIP accounts, making it the single communication tool.

Empathy also supports Telepathy, a unified framework for different kinds of real time communications. Client applications communicate over D-Bus messaging system which is simple and easy. Empathy also features Mission Control, a abstaract component for the UI to various chat accounts.

Empathy supports Video Chat effortlessly and out of box in most of the cases.