Web services technologies are advancing fast and being extensively deployed
in many different application environments. Web services based on the eXtensible
Markup Language (XML), the Simple Object Access Protocol (SOAP),
and related standards, and deployed in Service-Oriented Architectures (SOAs)
are the key to Web-based interoperability for applications within and across
organizations. Furthermore, they are making it possible to deploy applications
that can be directly used by people, and thus making the Web a rich
and powerful social interaction medium. The term Web 2.0 has been coined
to embrace all those new collaborative applications and to indicate a new,
“social” approach to generating and distributing Web content, characterized
by open communication, decentralization of authority, and freedom to share
and reuse.