Component Based Development (CBD) aims at constructing software through the integration, using interfaces and contracts, between pre-existing components. The main goal of this work is to provide access to component that can be published at the Web, retrieved, and reused in all phases of an application development within a given domain. We present an architecture for software components reuse by using a mediation layer that integrates the semantics of Web components with previously registered components from a virtual library of components. In our architecture, components are described through XML documents and published by local repositories or remote servers. The innovative aspect of our proposal is the combination of mediators and software agents for reusable component retrieval within a Domain Engineering context. Mediators can represent application domain as well as integrate the description of domain related components. Queries can be issued to the mediation layer and processed by the GOA Object Server, which presents the query results as a list of suggested components along with its repository link in XML. Software agents are responsible for web component discovery and filtering. Techniques such as user models (profiles), and recommendations are used for presenting a ranked list of links. Finally, resulting links from mediators and web post-processed results are combined and presented to the user.