In the late seventies at the Centre for Computers and Law research was started to find means for supporting lawyers' work with the aid of a computer. The research project was called JURICAS. In 1982 a prototype of a JURICAS system was produced and since 1986 seven advisory packages have been brought out on the market in the Netherlands. These packages consist of two main parts, an author's shell and an advisory program. The user cannot make changes to either the shell or the program. In 1988 the JURICAS author's shell became commercially available. A buyer has to make his own advisory program and fill it with his expertise to produce an advisory package. To facilitate the designing, the typing in and the testing of a package a number of utility programs are included in the author's system. An example of a self-developed legal computer advice system is a JURICAS system for Social Security Law. This system was written by two lawyers of a social security service in the Netherlands and helps with the processing of requests for social security. In May 1991 the computer advice system was put into use.