Collaboration in the digital domain offers an opportunity to provide enhanced digital services and extended reach to the community. This article adopts a service-oriented perspective through which it considers environmental drivers for digital library collaboration; discusses emergent collaborative partnerships across UK educational institutions, social services, health services, private industry, and cultural sectors; considers associated challenges; and identifies best practices. Existing and potential synergistic relationships are explored across the broader cultural sector--in particular, with the respective processes of libraries, museums, archives, arts and broadcasting organizations comprehensively identified and mapped (commonality), and the relationship to service-oriented architecture highlighted. The degree of digital service collaboration is also explored through an indicative review of Scottish public library websites, encompassing thirty-two regional library networks and including the National Library. Collaboration is found to be evident but limited in the digital domain, with strategic and architectural recommendations made. (Contains 2 figures and 6 footnotes.)