ES technologies come in various levels, they are:
- Expert System Development Environment
The ES development environment contains a set of hardware tools (Workstations, minicomputers, mainframes), High level symbolic programming languages [LISt Programming (LISP) and PROgrammation en LOGique (PROLOG)], as well as large data bases.
- Tools
Tools, as an ES technology, assists in reducing the effort and cost involved in developing an expert system to a large extent.
- Shells
A Shell an expert system that functions without a knowledge base. It provides developers with knowledge acquisition, inference engine, user interface, and explanation facility. For example – Java Expert System Shell (JESS), Vidwan, etc.