Software components and web services are software building blocks that are used in the composition of mod- ern software applications. They both provide functionalities that require to be advertised by registries in order to be discovered and reused during software building processes. Building or evolving existing software implies assembling software components. This task is not trivial because it requires to select the adequate component or service that provides some part of the desired application functionality and connects easily (with minimum adapta- tions) to other selected components. Within this context, we identified two main issues: (1) finding appropriate components from huge databases, and (2) creating and maintaining distributed applications.