Imake is a utility that works with make to enable code to be compiled and installed on different UNIX machines. Imake makes possible the wide portability of the X Window System code and is widely considered an X tool, but it's also useful for any software project that needs to be ported to many UNIX systems. Imake also runs under Windows NT. This Nutshell Handbook -- the only book available on imake -- is ideal for X and UNIX programmers who want their software to be portable. The book is divided into two sections. The first section is a general explanation of imake, X configuration files, and how to write and debug an Imakefile. The second section describes how to write configuration files and presents a configuration file architecture that allows development of coexisting sets of configuration files. Several sample sets of configuration files are described and are available free over the Net. New in the second edition: Updated to cover the current version of the X Window System (X11R6.1); Discusses using imake for non-UNIX systems such as Windows NT; Covers some of the quirks about using imake under OpenWindows/Solaris.