AbstractSolutions have been proposed to support awareness in groupware. Frequently, this requirement is fulfilled by similar functionalities that are implemented in different modules within these collaborative applications. These solutions usually represent crosscut concerns related to awareness by the use of object-oriented programming. As a result, tightly coupled components are generated as well as code redundancy and scattering. Flexibility and agility, related to awareness maintenance and evolution can be considered a challenge. This paper presents an awareness service named Aw2SOA, which was developed to support awareness functionalities in a Web-based Groupware Service-Oriented Architecture (WGWSOA) environment. The WGWSOA infrastructure is based on middleware services for collaborative applications. Aw2SOA is a middleware specific service which was implemented according to service-oriented architecture (SOA) principles and aspect-oriented programming (AOP) concepts. Case studies were carried out focusing on service integration activities as well as using groupware application development in order to evaluate this solution.