Russell and Burch's ‘3Rs’ principles of humane experimental technique - replacement, reduction and refinement - have been accepted widely throughout the world. Researchers generally recognize the need for a thorough search for, and wherever possible use of, alternatives to using live animals. Evidence that such searches have been undertaken is expected by ethical committees responsible for judging applications for research, and is required by law in the UK and some other countries. As written in the UK Animals (Scientific Procedures) Act 1986, ‘the Secretary of State shall not grant a licence unless he is satisfied (a) that the purpose of the programme to be specified in the licence cannot be achieved by any other reasonably practical method not entailing the use of animals … ‘. There have been developments in many fields of science in finding alternatives to the use of animals and a great deal ofinformation has been published on the subject. However, this information is scattered widely in the scientific literature and because of this, and the relative scarcity of good reviews, searching for information on alternatives in particular fields can be difficult. The world wide web now provides the potential for obtaining information on almost any subject very rapidly but the value of this remarkable resource is, as all of us have come to discover, limited by the capacities of the available machinery for searching and finding. The ‘web’ is like a colossal encyclopaedia with entries of very variable quality and a misleading and fragmentary index. Considerable efforts are being made by a variety of organisations to develop improved methods for extracting reliable and complete information on 3Rs alternatives and this book published by FRAME (see below) is a very useful review.