Google Wave

"Google Wave is "a personal communication and collaboration tool" announced by Google at the Google I/O conference on May 27, 2009.[1][2] It is a web-based service, computing platform, and communications protocol designed to merge e-mail, instant messaging, wiki, and social networking.[3] It has a strong collaborative and real-time[4] focus supported by extensions that can provide, for example, robust spelling/grammar checking, automated translation between 40 languages,[2] and numerous other extensions.[4] Initially released only to developers, a "preview release" of Google Wave has been extended to about 100,000 users on September 30, 2009."