REXX is a general purpose language which is easy to learn. It contains an extensive library of powerful functions which greatly reduces the amount of coding necessary to write applications. The use of REXX in a wide range of environments simplifies the writing of applications to run under different hardware and operating systems, and its expansibility allows other components to make use of REXX facilities and vice versa. A large part of the book is devoted to the use of REXX to interface with such components. Practical Usage of TSO REXX provides a concise source of information for the development and implication of applications using the REXX language. The author adopts a practical approach, using lists and diagrams to illustrate relevant points. This sixth edition has been revised to include examples of programmed functions written in Language Environment Assembler and C.