The paper illustrates the system WITH (Write on Internet clinical Trials in Haematology) which supports the writing of a clinical trial (CT) document. The requirements of this system have been defined analysing the writing process of a CT and then modelling the content of its sections together with their logical and temporal relationships. The system WITH allows: a) editing the document text; b) re-using the text; and c) facilitating the cooperation and the collaborative writing. It is based on XML mark-up language, and on a RDBMS. This choice guarantees: a) process standardisation; b) process management; c) efficient delivery of information-based tasks; and d) explicit focus on process design.