The following is a list of software packages and applications licensed under an open-source license or in the public domain for use in the healthcare industry.

Health Services Research Unit, Department of Public Health & Policy, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK 1Public Health & Clinical Quality Directorate, Department of Health, Richmond House, Whitehall, London SW1A 2NS, UK 2National electronic Library for Health, Institute of Health Sciences, University of Oxford, Old Road, Headington, Oxford OX3 7LF, UK Correspondence to: Dr John Powell E-mail: john.powell{at}lshtm.ac.uk To understand individual use of the internet and its impact on individuals, communities and societies is a challenge that is only beginning to be addressed.