It's taken several months, but Yahoo and Microsoft have finished adding the necessary ingredients to make their instant messaging services a palatable dish for consumers.
Rivals Yahoo and Microsoft have begun limited public beta testing of interoperability between Windows Live Messenger and Yahoo Messenger with Voice.
The cooperative effort, announced last October, is the first of its ilk between two major consumer IM providers and will cover some 350 million accounts, the companies said in a statement.
Microsoft and Yahoo users will be able to join the limited public beta program, which boasts all of the free amenities of a single IM service.
Services include message exchange, online presence, personal status messages, offline messages and the ability to add new contacts from either service at no cost.
"This first-of-its-kind interoperability between consumer IM leaders Microsoft and Yahoo gives our customers tremendous control, convenience and freedom in their Web communication experiences with Windows Live," said Blake Irving, corporate vice president of Windows Live Platform at Microsoft, in a statement.
Users of Windows Live Messenger and Yahoo Messenger with Voice in the U.S. and more than 15 markets all over the world can participate in the beta by visiting Yahoo or Microsoft.
The beta program will be available in the U.S., United Kingdom, Argentina, Australia, Brazil, Canada, China, France, Germany, Hong Kong, India, Italy, Korea, Mexico, Netherlands, Singapore, Spain, Taiwan and Turkey.
Yahoo and Microsoft aren't setting a specific timetable for general availability, other than to say the IM services will be available to all consumers in the coming months.
Joining forces could also curry favor with users of AOL's AIM services, easily the market leader in what has become a pretty competitive arena in the last few years.
While instant messaging services remain free for consumers, and are therefore not a direct revenue driver for software giants, they pose the potential for revenue-incurring services.
At the very least, IM platforms provide a window to a large customer base for targeted advertising.
While IM services used to be a text-only affair, Yahoo and Microsoft have been adding services to make them full-fledged communications systems, complete with audio and video.
Yahoo Messenger with Voice, for example, was the first to offer Webcam functionality and taps into a host of other Yahoo services, including PC-based calling, voice calling, e-mail, video or mobile messaging, games, music, photos and search.
Not to be outdone, Windows Live Messenger offers full-screen video, unlimited file sharing, text, video, mobile phone communication, photo access and search.