Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI.

), Microsoft Windows, and Mac OS X. Tkabber was started by Alexey Shchepin (also the author of ejabberd XMPP server) in 2002.

Several people contributed into it, notably Marshal T. Rose, Michail Litvak and Sergei Golovan, who is the current maintainer of the project.

In October 2004, Alexey Shchepin won an Honorable Mention for Tkabber in the ActiveState Programmer Network's Coolest Tk Screenshot Contest.

The goal of the Tkabber project is to create a cross-platform XMPP client which is feature-rich and is easy to hack.