Expert systems, a branch of artificial intelligence, have seen tremendous growth over a long period of time. The application of technology has cut across different sectors of society and made possible by using various software tools. This article critically reviewed the application of software tools in the development of an expert system for use in different sectors. Key issues of focus included tools used, application areas, and the implementation environment. A structured approach to the systematic review was adopted that involved formulation of research questions, establishment of criteria for inclusion & exclusion, undertaking a search, selection of articles to be reviewed, assessment of the quality of articles, extraction of data, and analysis of the data. Articles published in English from 2018 to 2022 from journals, conference proceedings, and book series were reviewed. Findings from the review pointed to a widespread application of expert systems globally, developed using several tools. CLIPS, Prolog, Jess, and MATLAB emerged as the preferred tools for the development of expert systems. The implementation of the expert systems involved the independent use of the tools and their integration with other software environments. The different software integration pathways used with the tools have also been highlighted. This review provides insights into the state of research relating to the development of expert systems and their applications.