The fourth edition will be updated to account for new developments since 2000. In addition its accompanying software is based on PIKS Scientific rather than PIKS Core. The CD will contain all of the contents of a 500 page PIKS Scientific Software Manual developed by the author, in addition to the executable PIKS Scientific software. This is a great value to the purchaser who will be able to acquire a full feature software package for the price of the book - a fraction of the commercial package.