ADE-4 is a multivariate analysis and graphical display software designed for Apple Macintosh and Windows 95 microcomputers. It consists of several standalone modules, including computational and graphical modules, that offer a wide range of multivariate analysis methods and graphical display techniques. The software supports various one-table methods such as principal component analysis (PCA) and correspondence analysis, spatial data analysis, discriminant analysis, linear regression, multiple and PLS regression, orthogonal regression, projection methods, canonical correspondence analysis, coinertia analysis, and three-way table analysis. It also provides interactive graphical capabilities, including automatic collection of elementary graphics, dynamic graphic modules for searching, zooming, selection, and data value display on factor maps. The user interface is simple and homogeneous, making it accessible to non-specialists in statistics, data analysis, or computer science. ADE-4 is freely available on the internet and can be used in various scientific disciplines beyond environmental data analysis. The software includes a HyperCard stack (ADE-4Base) for launching modules and navigating through example data sets and a bibliography stack (ADE-4Biblio) with over 800 references on statistical methods and data sets.ADE-4 is a multivariate analysis and graphical display software designed for Apple Macintosh and Windows 95 microcomputers. It consists of several standalone modules, including computational and graphical modules, that offer a wide range of multivariate analysis methods and graphical display techniques. The software supports various one-table methods such as principal component analysis (PCA) and correspondence analysis, spatial data analysis, discriminant analysis, linear regression, multiple and PLS regression, orthogonal regression, projection methods, canonical correspondence analysis, coinertia analysis, and three-way table analysis. It also provides interactive graphical capabilities, including automatic collection of elementary graphics, dynamic graphic modules for searching, zooming, selection, and data value display on factor maps. The user interface is simple and homogeneous, making it accessible to non-specialists in statistics, data analysis, or computer science. ADE-4 is freely available on the internet and can be used in various scientific disciplines beyond environmental data analysis. The software includes a HyperCard stack (ADE-4Base) for launching modules and navigating through example data sets and a bibliography stack (ADE-4Biblio) with over 800 references on statistical methods and data sets.