IM, instantmessaging, instant Messaging.
Now, there are a number of companies that provide instant messaging capabilities on the market. such as: full-time, cloud, Jong communication, cloud, ring letter, etc., from the Internet a search, can search out a lot of. Perhaps you think, how to develop an IM system so simple, why so many companies have done so well? Actually, these products, in fact, are based on a long time ago, an open source technology, Jabber.
Jabber is an Instant Messaging server technology that Jeremiemiller started in 1998 and released in May 2000. At first it should be on Linux only and now it can be run on Windows.
The Jabber server is distributed and the user communicates through the server. Also, users of different servers can communicate with each other. Like Google's Gtalk, MSN, ICQ, etc., can communicate with the users of the Jabber server.
Above said so much, like we use the ring letter of the IM function, or very stable. And there are many users in use, this is verified, do not worry too much about this aspect of the problem.
The current daily activity of the ring is below 300,000 and is free of charge. More than this number, every 100,000 days active users of the charge for 5000 yuan/month.
APP IM's XMPP and Jabber