An introductory tutorial to APL, an extremely concise and powerful computer programming language. The book has been adapted to fit most commercial APL systems, including IBM's VS APL, I.P. Sharp's SHARP APL, and STSC's APL PLUS Systems. Concentrating on elements of the language common to all of them, readers will quickly learn how to store data and make the computer ``talk'' to them; set up an electronic checkbook to analyze bank statements; write programs for reports, and produce bar charts. Sections also cover formatting with the system function FMT, a technique which allows for more control over printing. Also provides additional programming tools, including the use of ``friendly'' interactive systems.