MSN Messenger

Windows Live Messenger (formerly named MSN Messenger) is an instant messaging client created by Microsoft that is currently designed to work with Windows XP (up to Wave 3), Windows Vista, Windows 7, Windows Mobile, Windows Phone, Windows CE, Xbox 360, Blackberry OS, iOS, Java ME, S60 on Symbian OS 9.x, and Zune HD. 

The client has been part of Microsoft's Windows Live set of online services since 2005. It connects to Microsoft's .NET Messenger Service. The client was first released as MSN Messenger on July 22, 1999, and as Windows Live Messenger on December 13, 2005. 

Windows Live Messenger is free to download and is available in 26 languages and is used in more than 60 countries by more than 240 million active accounts each month.

QIP

QIP (an acronym for Quiet Internet Pager) is a multiprotocol instant messaging client. It is a closed source freeware program originally developed by Ilgam Zyulkorneev. In 2008 it was bought by RosBusinessConsulting media group and named most popular RBC service in 2009. 

QIP 2005 unique feature (at the time) : tabbed message windows -- instead of a message window for each chat session, one window with several tabs is shown. Since this feature's introduction, ICQ Version 6.0 now includes this feature, as do the multi-service clients Pidgin, Miranda IM, and Trillian. Other features include integrated mail.ru e-mail client, and a wider range of emoticons. QIP presents no advertisements in the application windows; this is described as a security advantage.

QIP Infium is the second version of QIP. It features full Unicode support and is multi-protocol client, supporting the following protocols:

• OSCAR: ICQ
• XMPP, first stolen and only then licensed on Miranda IM Jabber Plug-in with preinstalled settings for QIP, LiveJournal, Google Talk
• XIMSS (CommuniGate Pro IM and VoIP protocol) with preinstalled settings for QIP, SIPNET and Euroset
• Mail.ru Agent
• IRC (Additional plugin)

QIP Infium attempts to reset Internet Explorer to use the search engine at the QIP homepage (currently written in Russian). This feature can be disabled on the first attempt or by using the Add-on Manager under the Tools menu of Internet Explorer.

New version of QIP named QIP 2010 contains all features of Infium and interface of QIP 2005.