The authors seek to establish a simple and flexible framework for internal representation of language-dependent information, and the behavior of language-oriented tools for user's operations. They present a system for generating language-oriented editors based on object-oriented concepts. Features of the target language are represented as classes and their relations. A program is represented as an abstract syntax tree. Each node in the tree belongs to a node class. For generating more advanced editors, probes, internal-classes, and gates are incorporated into the system. The system generates a flexible and easily extendable language-oriented editor from a target language description in a highly modularized fashion by using the description language which the system provides.>