This article describes a computer-based writing assistant called REVISE, which implements some “Plain English” guidelines in an easy-to-use, efficient computerized tool. Some existing computer-based writing systems are reviewed and some problems with these systems are discussed, particularly in the area of the human-computer interface. The article describes the design principles that formed the basis of REVISE and how REVISE improves upon some of the difficulties noted in the existing systems. A preliminary evaluation of the effectiveness of REVISE is described. Some limitations of REVISE are discussed as are directions for future research and development on computer-based writing aids.