E-services, and in particular Web services, are emerging as a promising technology for the effective automation of application integration across networks and organizations. The basic technological infrastructure for e-services is structured around three major standards: SOAP, WSDL, and UDDI. These standards provide building blocks for service description, discovery, and interaction. E-service technologies have clearly influenced positively the development of integrated systems by providing programmatic access to e-services through SOAP, WSDL, and UDDI. E-services are evolving toward being able to solve critical integration issues including security, transactions, collaborative processes management, semantic aspects, and seamless integration with existing middleware infrastructures.