The AMPL processors and solvers in this directory are "student" versions that restrict problem sizes (to 300 variables and 300 general constraints) and are intended for noncommercial use. For serious commercial use, you should (eventually) license commercial versions, even if your applications never exceed the limits of the student versions. See the AMPL web site http://www.ampl.com for extensive information about AMPL, including descriptions of extensions available in current versions and pointers to information about other solvers. Files with names ending in ".gz" were compressed by gzip, and cplex.tgz is a tar file compressed by gzip and containing both a LICENSE file and a cplex binary. In general, you need to decompress the *.gz files and make them executable. For example, you could execute gzip -dN ampl.gz cplex.tgz lpsolve.gz minos.gz tar xf cplex.tar chmod +x ampl cplex lpsolve minos rm cplex.tar You may also need to move the files (using "mv" or "cp") to a directory on your search PATH. File ampl is a student version of the AMPL processor. File cplex is a student version of CPLEX 7.1 (for use with ampl). For pointers and more details, see files README.1st, README.cplex, and ampl110.pdf in directory /netlib/ampl/solvers/cplex. Please note that ampl70.pdf refers to "cplexamp" rather than "cplex". Unrestricted versions of cplex sold by ILOG/CPLEX are called "cplexamp" when delivered. You are free to name things as you wish (with suitable changes to "option solver" lines in AMPL scripts if necessary). One approach that avoids changes to AMPL scripts is to call the interactive CPLEX front end provided by ILOG/CPLEX "icplex" rather than "cplex", and to use "cplex" for the solver that works with AMPL. File minos is a student version of MINOS (for use with ampl). For pointers and more details, see files README.1st and README.minos in directory /netlib/ampl/solvers/minos and see web page http://www.ampl.com/REFS/abstracts.html#ampl-minos . File lpsolve is a solver based on lp_solve, an LP and MIP solver by Michel Berkelaar. For pointers and more details, see /netlib/ampl/solvers/lpsolve/README. File snopt is a student version of SNOPT (for use with ampl). For pointers and more details, see file README in directory /netlib/ampl/solvers/snopt.