The advent of personal computers (leading to the emergence of the CD-ROM and the World Wide Web) has revolutionised the ability to communicate with and access large data bases rapidly and efficiently. Examples of the provision of CD-ROMs and the implementation of the Web are listed in Appendix A (ENSDF, NUBASE and the Table of Isotopes). A significant number of these data bases have been adapted so that PCs can interrogate, extract, compare and use their contents. Both the Internet and the utilisation of CD-ROMs have given users world-wide access to all of the most recently evaluated nuclear data libraries via a number of routes including the IAEA Network of Nuclear Data Centres. Communications between laboratories have improved beyond all recognition over the previous 10 years, and have revolutionised the speed with which data can be provided for various calculations (including decay — heat analyses).