Social networking site MySpace is releasing a set of APIs later today that will allow developers to implement protocols for exchanging and synchronizing user profiles between their own applications and MySpace profiles. Users can share their basic profile information, as well as their MySpace photos, videos, and friend list.

As we reported earlier, MySpace has signed up a number of high profile partners for this launch: Yahoo, Twitter, eBay and Photobucket.

This is, of course, a direct competitor to Google's Friend Connect and Facebook's Facebook Connect, though, as Steve O'Hear notes on ZDNet, there are important differences between these projects. While Friend Connect relies on an iframe to exchange data between sites, the Data Availability APIs makes third-party services request the data from MySpace 'on the fly' and only allows a user's login name to be cached.

As Steve notes, if MySpace's Data Availability API is adopted by a large enough number of sites, it could make MySpace the de facto host for social network profiles.

The details around Facebook Connect