In the last few years, the business web has clearly taken hold with many successful companies offering applications or software as services. CRM and HR applications, in particular, have paved the way, with companies of all sizes are using software as a service (SaaS) and managed service applications for many strategic business initiatives such as customer management and recruitment management. The success of SaaS and managed services has partly occurred because of market acceptance, but mostly because technology does matter. We are on the verge of a new era of applications resulting directly from the convergence of three trends: web services, XML and service-oriented architectures (SOA).