Knowledge Engineering Environment

{{Infobox software

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| developer = IntelliCorp

| released = {{Start date and age|1983}}

| discontinued = Yes

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| programming language = Common Lisp

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| platform = Symbolics Lisp Machine, TI Explorer Lisp Machine, HP 9000 Series 700 and 800 workstations, the Sun

SPARCstation and IBM RS6000 workstation

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| language = English

| genre = Expert system development tool

| license = Proprietary

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{{Use dmy dates|date=October 2017}}

Knowledge Engineering Environment (KEE) is a frame-based development tool for expert systems.{{cite book |url=http://portal.acm.org/citation.cfm?id=62001 |title=An evaluation of expert system development tools|year=1989 |publisher=Ablex Publishing Corp. |isbn=9780893914943 }} It was developed and sold by IntelliCorp, and was first released in 1983. It ran on Lisp machines, and was later ported to Lucid Common Lisp with the CLX library, an X Window System (X11) interface for Common Lisp. This version was available on several different UNIX workstations.

On KEE, several extensions were offered:

• Simkit, a frame-based simulation library{{cite book |chapter=The SimKit system: knowledge-based simulation and modeling tools in KEE|doi=10.1145/76738.76766|title=Proceedings of the 21st conference on Winter simulation - WSC '89|pages=232–234|year=1989|last1=Stelzner|first1=M.|last2=Dynis|first2=J.|last3=Cummins|first3=F.|isbn=0911801588|s2cid=18125370 |chapter-url=http://www.lib.ncsu.edu/resolver/1840.4/5006}}{{cite book |url=http://portal.acm.org/citation.cfm?id=62001 |title=SimKit: a model-building simulation toolkit|year=1989 |publisher=Ablex Publishing Corp. |isbn=9780893914943 }}
• KEEconnection, database connection between the frame system and relational databases{{cite book |url=http://portal.acm.org/citation.cfm?id=62001 |title=KEEConnection: a bridge between databases and knowledge bases|year=1989 |publisher=Ablex Publishing Corp. |isbn=9780893914943 }}

In KEE, frames are called units. Units are used for both individual instances and classes. Frames have slots and slots have facets. Facets can describe, for example, a slot's expected values, its working value, or its inheritance rule. Slots can have multiple values. Behavior can be implemented using a message passing model.

KEE provides an extensive graphical user interface (GUI) to create, browse, and manipulate frames.

KEE also includes a frame-based rule system. In the KEE knowledge base, rules are frames. Both forward chaining and backward chaining inference are available.

KEE supports non-monotonic reasoning through the concepts of worlds. Worlds allow providing alternative slot-values of frames. Through an assumption-based truth or reason maintenance system, inconsistencies can be detected and analyzed.{{cite book |url=http://portal.acm.org/citation.cfm?id=62001 |title=Reasoning with worlds and truth maintenance|year=1989 |publisher=Ablex Publishing Corp. |isbn=9780893914943 }}

ActiveImages allows graphical displays to be attached to slots of Units. Typical examples are buttons, dials, graphs, and histograms. The graphics are also implemented as Units via KEEPictures, a frame-based graphics library.