This volume constitutes the proceedings of the 10th International Workshop on Groupware (CRIWG 2004). The conference was held in San Carlos, Costa Rica, and followed the traditional CRIWG spirit: a relatively small number of attendees, lively discussions and participation during and between paper p- sentations, and a constructive and friendly environment, which promoted a high level of learning and collaboration. The previous nine CRIWG workshops were organized in Lisbon, Portugal (1995), Puerto Varas, Chile (1996), El Escorial, Spain (1997), Buzios, Brazil (1998), Cancun, Mexico (1999), Madeira, Portugal(2000), Darmstadt, Germany (2001), La Serena, Chile (2002), and Autrans, France (2003). This 10th anniversary CRIWG exempli?ed the continuing interest in the groupwareresearcharea.Groupwareresearchersfrom 14 di?erent countriess- mitted a total of 71 papers. Each of the 71 papers was reviewed by two to three members of an international Program Committee, using a double-blind revi- ing process. Reviewers were carefully matched to paper submissions as much as possible to ensure expert assessments of the submitted research while avo- ing potential con?icts of interest. Reviews were usually extensive and contained many constructive suggestions for improvement. Based on the reviewers' rec- mendations 29 papers were ?nally accepted: 16 long papers presenting mature work, and13shortpapersdescribingworkinprogress.Theacceptedpaperswere grouped into seven themes that represent current pockets of interest in gro- wareresearch: knowledgemanagement, awareness, supportforcollaborationp- cesses, collaborativeapplications, groupwareinfrastructure, computer-supported collaborative learning, and mobile collaborati