Interfaces to databases have traditionally been designed as single-user systems that hide other users and their activity. This paper aims to show that collaboration is an important aspect of searching online information stores that requires explicit computerised support. The claim is made that a truly user-centred system must acknowledge and support collaborative interactions between users. Collaborative working implies a need to share information: both the search product and the search process. Searches need not be restricted to inanimate resources but people can also search for other people. The ARIADNE system is introduced as an example of computerised support for collaboration between browsers. A number of systems offering varied approaches to supporting collaboration are surveyed and a structure for analysing the various aspects of collaboration is applied.