At yesterday's Web 2.0 Expo keynote, Yahoo's CTO Ari Balogh announced YOS, Yahoo Open Strategy, a major transformation that will ultimately give developers access to a vast array of Yahoo services including mail, sports, search, the Yahoo home page, mobile, My Yahoo and others. It's an ambitious "rewiring" of Yahoo that includes development tools, an application Platform, and unified social profiles.
The first public piece of this effort is the project code-named Search Monkey, initially announced back in February: an extensible, open approach to search. Later this year Yahoo will unveil Y!Open which among other things will expose social network services and tools for developers including news Feed-style streams, which they refer to as "vitality".
Although this announcement comes only days after Google announced iGoogle is becoming a social network, Ari stated that "We are not creating another social network. We will rewire the entire experience to make it social. We don't think of social as a destination but as a dimension."
Yahoo's Neal Sample provides more background on Yahoo's blog and you can view the Ari's Web 2.0 Keynote here:
Yahoo used the occasion to remind folks just how vast their reach is: 500 million unique users and 120 pageviews per month. And with 10 billion relationships on Yahoo buddy lists and address books, "there’s a massive, latent social network within Yahoo!, and we’re going to bring it to the surface".