The importance of the ability to measure the performance of programs written in high-level languages is well known. Performance measurement enables users to locate and correct program inefficiencies where automatic optimizations fail and provides a tool for understanding program behavior. This paper describes performance measurement facilities for the Icon programming language, and shows not only how these facilities provided insight into program behavior, but also how they were used to improve the implementation.

Abstract The special editing ability of display terminals is seldom exploited outside of display‐based text editors. Tailoring a device driver in the operating system kernel to display terminals makes display editing available whenever the terminal is used and makes display editors simpler and terminal‐independent. This paper describes such a device driver.