The development of groupware product lines entails, beyond the detailed knowledge of the application domain, analysis of the collaboration that they should support. To attack this problem, this research uses the 3C Collaboration Model that underlies the RUP 3C-Groupware on domain analysis phase. For the implementation phase, this model is still being used, this time based on Groupware Workbench. This approach illustrates the use of the collaboration model at all stages of the product line development. It provides a systematic way for tailoring groupware, using the concept of software product lines.