This volume presents the proceedings of the 15th International Workshop of Groupware (CRIWG 2009). The conference was previously held in USA, (- aha)in 2008, Argentina (Bariloche)in 2007, 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 seek to advance theoretical,...