Nowadays e-learning is becoming more important as it makes possible the dissemination of knowledge and information through the internet in a faster and costless way. Consequently, in order to filter what is more relevant and/or of users interest, architectures and personalization techniques have been raised. Among the many existing possibilities of personalization, the one that deals with accessibility is becoming essential because it guarantees that a wide variety of users may have access to the information according to their preferences and needs. Accessibility is not just about ensuring that disabled people can access information, although this is important and may be a legal requirement. It is also about ensuring that the wide variety of users and devices can all gain access to information, thereby maximizing the potential audience. This dissertation presents an extension of LORIS, an integration system of learning object repositories, describing the changes on its architecture to make it able to deal with accessibility and to recognize different versions of the same learning object, thus allowing a user to execute a query considering his/her preferences and needs. A prototype of the services that are described in the architecture was developed using web services and faceted navigation, as well as e-learning and accessibility standards. The use of web services and standards aims at providing flexibility and interoperability, while the faceted navigation, as implemented, allows the user to apply multiple filters to the query results without the need to resubmit it.