AEZWIN stands for AEZ for Windows. This report, previously issued as World Soil Resources Report No. 87, presents the recently developed Windows-based software package for agro-ecological zoning analysis at the national and subnational levels, including models for land suitability and land productivity assessment and a user interface to multi-objective land use optimization. The software package allows models to be generated interactively corresponding to various scenarios of land use and then to be analysed using modular multiple-criteria model analysis tools. The package is illustrated by the example of a detailed Kenya AEZ study. System requirements: Pentium PC; 32 bit MS-Windows; 32 MB RAM and 100 MB disk space;15display supporting a resolution of 1024x768