This special thematic section of the Journal of Computer-Mediated Communication brings together seven articles that consider what it takes to collaborate around and through information and communication technologies. The authors consider how processes co-evolve between practices and technical systems, how knowledge is shared across organizational, cultural and geographic boundaries, how conversation via the informal medium of Instant Messaging is being adopted into organizational practices, what motivates participation in large distributed computing projects, and how computer media can change the nature of interactivity in classrooms. The articles cover a range of applications and settings; as a collection, they draw our attention to the broad interpretation that can be giving to the meaning of collaboration.