Abstract. The sharing of content by communities of users (e.g., scientists) in a P2P context remains cumbersome. We argue that main reasons for this is the lack of calculus and algebra for distributed data management. We present the ActiveXML language that extends the XML language with features to handle distribution. More precisely, ActiveXML documents are XML documents with a special syntax for specifying the embedding of Web service calls, e.g. XML queries such as XQueries. We also present ActiveXML algebra that extends ActiveXML notably with explicit control of data exchanges. ActiveXML algebra allows describing query plans, and exchanging them between peers. Keywords. distributed data management, XML, Web, Web service, calculus, algebra, monitoring, stream. The field of distributed data management [17] has centered for many years around the relational model. More recently, the Web has made the world wide and intranet publication of data much simpler, by relying on HTML, Web brows...