Web 2.0 and service oriented architecture (SOA)'s philosophy and their respective applications from technological and business perspective are presented. SOA is considered the philosophy of encapsulating application logic in services with a uniformly defined interface and making these publicly available through discovery mechanisms. SOAs allow for a cross-organizational integration of services. Corporations are enabled to setup loosely coupled electronic business transactions with other companies and thus automate business transactions in a quickly changeable fashion adhering to common standards for the description of their service interfaces. Both the services let users reuse, remix, and enrich existing resources and components to new and potentially higher-level applications. The philosophies of Web 2.0 and SOA serve different user needs and thus expose differences with respect to the design and used technologies of real-world applications.