This paper introduces a framework for awareness support in groupware systems. Awareness gathers the group knowledge, its activities and its overall status. Awareness support is an important feature for groupware systems. It provides a context for individual contributions, improving these contributions and avoiding contradictory interactions among group members. Despite its importance, awareness support is not systematic and developers must build it from scratch for each new application. The framework presented here addresses this issue. This framework, called Big Watch (BW), intends to support groupware implementers to easily build past event awareness mechanisms. It has been designed to develop new groupware applications and to improve existing ones. This paper presents the features and the structure of BW, and describes two applications that use it.