Mail.Ru Agent is a free instant messaging program created by Mail.ru

Mail.ru

Mail.ru is the largest free e-mail service of the Runet. The business was originally owned by Port.ru, a company founded in 1998 by Eugene Goland, Michael Zaitsev and Alexey Krivenkov as spin-off from DataArt. It received an initial investment of USD 1 million from the well-known investor James...

, one of the largest Russian web portals. Besides basic IM functionality (presence, contact list

Contact list

A contact list is a collection of screen names in an instant messaging or e-mail program or online game or mobile phone. It has various trademarked and proprietary names in different contexts....

, sending text messages, file transfer

File transfer

File transfer is a generic term for the act of transmitting files over a computer network or the Internet. There are numerous ways and protocols to transfer files over a network. Computers which provide a file transfer service are often called file servers. Depending on the client's perspective the...

s, message history, etc.), M-Agent also provides online gaming

Online game

An online game is a game played over some form of computer network. This almost always means the Internet or equivalent technology, but games have always used whatever technology was current: modems before the Internet, and hard wired terminals before modems...

, peer-to-peer

Peer-to-peer

Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads among peers. Peers are equally privileged, equipotent participants in the application...

 voice calls, video calls, low-rate VoIP calls, free SMS

SMS

SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...

, automatic mail checking and other useful features.

Mail.Ru Agent runs under Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 and communicates with server using proprietary (but partially documented) protocol called MMP that works over TCP/IP.