The program suite is supplied as source code that must be compiled on the user's computer. This requires knowledge of Unix, system management, and access to Administrator privilege on the machine. It also requires Fortran 77 and Ansi C compilers (the GNU versions g77 and gcc are ideal). The full TOPOG package will only run under UNIX including the Cygwin shell for MS Windows. We recommend a workstation with the following specifications: - at least 32 Mb core memory, preferably 64 Mb - at least 100 Mb free disk space, preferably 200 Mb - a high resolution colour graphics monitor, preferably 1280 x 1024 pixels, in a 19 inch format TOPOG consists of over 30 FORTRAN and C programs. Some of the programs are interactive, entailing the use of mouse-driven menus and high level graphics functions. The screen graphics routines and user interface are written in X-WINDOWS and MOTIF.