There are several levels of ES technologies available. Expert systems technologies include −
● Expert System Development Environment − The ES development environment includes hardware and tools. They are −
○ Workstations, minicomputers, mainframes.
○ High level Symbolic Programming Languages such as LISt Programming (LISP) and PROgrammation en LOGique (PROLOG).
○ Large databases.
● Tools − They reduce the effort and cost involved in developing an expert system to large extent.
○ Powerful editors and debugging tools with multi-windows.
○ They provide rapid prototyping
○ Have Inbuilt definitions of model, knowledge representation, and inference design.
● Shells − A shell is nothing but an expert system without knowledge base. A shell provides the developers with knowledge acquisition, inference engine, user interface, and explanation facility. For example, few shells are given below −
○ Java Expert System Shell (JESS) that provides fully developed Java API for creating an expert system.
○ Vidwan, a shell developed at the National Centre for Software Technology, Mumbai in 1993. It enables knowledge encoding in the form of IF-THEN rules.