Bioinformatics activities are growing all over the world, with proliferation of data and tools. This brings new challenges: how to understand and organize these resources and how to provide interoperability among tools to achieve a given goal. We defined and implemented a framework to help meet some of these challenges. Four issues were considered: the use of Web services as a basic unit, the notion of a Semantic Web to improve interoperability at the syntactic and semantic levels, and the use of scientific workflows to coordinate services to be executed, including their interdependencies and service orchestration.