This is GEPASI 2.0, a general purpose simulator of metabolic pathways. It is a directed towards research and education; it is meant to be a very useful tool for modelling biochemical pathways, chemical reactions,etc. GEPASI is free software covered by the GNU general public license, version 1. This version of GEPASI runs under MS-Windows 3.1 in 386 enhanced mode, on 80386SX and above microprocessors. A maths co-processor is not needed but should accelerate the simulations by at least a factor of 10. To install GEPASI unzip all the files to a diskette or to a hard-disk directory; there is no need to do this if you have received GEPASI in a diskette. Next go to Windows' program manager, select File-Run, and enter SETUP.EXE (don't forget to include the complete path of the disk drive and directory where you have unzipped it to). In order to simulate bichemical pathways, the user must first define the reactions that are part of the pathway, all its parameters and initial concentrations of the metabolites (chemical species). GEPASI then determines the dynamics and steady state (if there is one), including the coefficients defined in Metabolic Control Analysis. GEPASI can be used to study metabolic regulation, chemical and enzyme kinetics including oscillatory (limit cycle) and chaotic reactions. The file GEPASI.WRI contains a cut-down version of a paper to appear in "Modern trends in Biothermokinetics", edited by J.-P. Mazat, S. Schuster and M. Rigoulet and published by Plenum Press with a short description of GEPASI. Another more detailed paper is being submitted to the journal "Computer Applications in the Biosciences". For more detailed information see the help file (GEPASI.HLP). The subjects of metabolic simulation and metabolic control analysis are discussed in the mailing list btk-mca. To subscribe to this list send a mail message to biosci@net.bio.net, post to the list to btk-mca@net.bio.net. GEPASI 2.0 (c) 1898,1992 by Pedro Mendes. prm@aber.ac.uk