Google Talk is an instant messaging system as well as the associated software client that developed by Google Inc..
Gmail users can use it to communicate in real time through text messages or voice. Google Talk is based on the XMPP protocol, which was developed by the XMPP Standards Foundation as an open instant messaging protocol and was expanded from Google to the VoIP functionality under the name jingle. Therefore, it was still possible until May 2013, to use the service in addition to the official client program using any other XMPP client.
There is a Google Talk software for Android, bada, HP webOS, BlackBerry OS, Nokia Internet Tablets, for Apple iOS via Truphone, as well as for the Sony Mylo.
Also iChat 4.0 ( part of Mac OS X Leopard) support Google Talk.
The introduction of the Google Talk service was preceded by some rumors and speculations; as advertised Google in January 2005 for the post of VoIP experts and shortly before the launch of the service on 24 August 2005 it was reported in many Internet forums about having a XMPP server on talk.google.com and the XMPP standard port 5222 with an XMPP typical refusal to login attempts answered.
Since January 17, 2006 Google Talk has been extended to the possibility of connection to other XMPP servers and now allows communication between XMPP and Google Talk users. Thus also is the communication with users of the provider GMX, Web.de, Earthlink, Gizmo5, Tiscali, NetEase, Chikka, Media Ring possible, or to support their working. Also, Google plans to implement the cross-network communication with users external messaging services to their clients, for the time being but will that be limited to AIM.
Since May 16, 2006, a German version of the software.
In addition to the interconnection with other networks, among others, the implementation of the SIP protocol is planned, as well as a documentation of Google's XMPP implementation or the Jingle extension was recently published.
In June 2012, Google announced that they plan to Google Talk with Google Hangout Google Messenger and bring together the fragmentation of their products, as well as to reduce the resulting confusion of the users. The XMPP support was rather with this step in May 2013.