In this book we focus on the problem of semantically accessing distributed information concerning e-service management and Information System interoperability. Specifically, we describe AESM (Adaptive E-Service Manager), a platform based on both Intelligent Agent technology and XML whose goal is to adapt service delivery to both exigencies of users who are benefiting from the services and the technical features of the devices they are exploiting. AESM analyzes both user- and device- related information and, then, is capable of both selecting and suitably presenting the most relevant information contents for the user. We then illustrate XIKE (XML Intensional Knowledge Extractor). This system proposes a suitable formalism for describing the contents of an XML Schema and exploits suitable graph-matching algorithms for detecting a wide range of interschema properties (i.e., synonymies, homonymies, hyponimies, overlappings and sub-schema similarities) existing between two (or more) XML Schemas. XIKE exploits interschema properties for carrying out both the integration and the clustering of involved XML Schemas.