KB is a frame-based knowledge representation package. It is written as a Common Lisp package, and is comprised of a set of functions for representing semantic knowledge and relationships among data represented. KB encourages the use of the object-oriented programming metaphor by requiring that a set of operators be defined for each concept (object). Inheritance is supported for both data types and for operators. KB has a well-defined programming interface through which a user interface language can be easily developed. The semantics of KB are straightforward and allow a programmer considerable flexibility in developing an application. KB borrows heavily from the Flavors system in syntax and semantics (and in documentation!).