What kind of online services XdbE is designed for? Is it only for social networks or other types of sites like blogs or forums can participate as well?
XdbE is primarily designed to assist so-called OCS (Online Community Services) or in other words all websites where users can establish friendship relationships with each other. Web sites of this type will obviously benefit most from functionality offered by XdbE but the system is open for all other types of services where users can register and publish their content including but not limited to such types as free standing blogs, forums and other similar services. Such services may benefit at the level of registering their so-called AKA data as well as accessing XdbE.
