The first persistent Web agent that we have created on Actor Prolog is a program that collects information about research groups that develop Prolog and projects in the field of logic programming. The agent looks through a given list of Web sites and calculates some attributes of the sites: the date of recent modification, total size, the number of figures, the number of outside links, the number of error links, the number of given keywords, etc. ... http://www.cplire.ru/Lab144/space/prolog.html . ...