rm writes "Internet search and mail provider Yandex, which many view to be Google's main competitor in Russia, has recently added an instant messaging capability to its mail notifier application Ya.Online. As it turns out, the IM service is based on the open XMPP protocol, with connectivity to all other public Jabber servers available from day one. MacOS X and GNU/Linux versions of the app were also released (complete with sources under the GPL) and are determined to be based on the Psi IM client. Yandex looks to be a firm believer in open-source, also running a mirror site for FOSS and actively promoting its branded version of Firefox. Here's hoping that its affair with XMPP will help eliminate ICQ's enormous foothold in Russia."