This volume constitutes the proceedings of the 13th International Workshop on Groupware (CRIWG 2007). The conference was held in Spain (Medina del Campo) in 2006, Brazil (Porto de Galinhas) in 2005, Costa Rica (San Carlos) in 2004, France (Autrans) in 2003, Chile (La Serena) in 2002, Germany (Darmstadt) in 2001, Portugal (Madeira Island) in 2000, Mexico (Cancun) in 1999, Brazil (Buzios) in 1998, Spain (El Escorial) in 1997, Chile (Puerto Varas) in 1996, and Portugal (Lisbon) in 1995. The CRIWG workshops have been motivated by advances in computer-supported cooperative work (CSCW), and by the need for CSCW to meet the challenges of new application areas. This workshop aims at providing a forum for academic researchers and professionals to exchange their experiences and their ideas about problems and solutions related to the design, development and use of groupware applications. - searchers report their ideas, models, designs and experiences to CRIWG submitting full-paper contributions to present achieved or mature works, and shorter papers to report work in progress.