Critical factors in the evolution of logic programming and Prolog

Logic programming has received much critical attention over the past two decades from both a language perspective and as a methodology for practical problem solving. This paper presents a historical foundation of the approach and examines the development of Prolog since its first implementation. An analysis of the use of Prolog in commercial, research and teaching environments shows that there is an established base of users and that, after a period of rapid growth, the language currently enjoys continuing activity. The key to its success so far is due to its continuing evolution by including features that were not seen as being within the original concept as a pure logic language. Significant features which have contributed to the success of Prolog include integration with other languages, object oriented extensions, constraint representation, parallel execution as well as improved speed and robustness. Applications databases are analysed with respect to type of application, system status, type of developer, hardware platform, country of origin and the Prolog implementation used. Factors contributing to the success of Prolog are identified and likely future developments are explored.