LEXICO is an interactive system which assists lexicographers in storing, editing, and concording texts; lemmatizing word lists; and generating slips. A slip is equivalent to a file card and contains a single word from a text, and its lemma, context, and source. From a file of such slips (sometimes running into the millions), plus supportive reference materials and word studies, dictionary editors compile entries for a dictionary. The system, developed originally as a research tool for exploring different approaches to man-machine integration in lexical processing, has now been implemented as a user system at the Madison Academic Computing Center, University of Wisconsin. Recent applications of the system include studies of style in Modern French literature and text processing for the Dictionary of Old English. The present article presents a sampling of the capabilities of LEXICO, with emphasis on interaction techniques and user aids.