Provides additional data sets, methods and documentation to complement the 'vcd' package for Visualizing Categorical Data and the 'gnm' package for Generalized Nonlinear Models. In particular, 'vcdExtra' extends mosaic, assoc and sieve plots from 'vcd' to handle 'glm()' and 'gnm()' models and adds a 3D version in 'mosaic3d'. Additionally, methods are provided for comparing and visualizing lists of 'glm' and 'loglm' objects. This package is now a support package for the book Friendly, M. and Meyer, D. (2016, ISBN:978-1-4987-2583-5) 'Discrete Data Analysis with R: Visualization and Modeling Techniques for Categorical and Count Data'. Recent work adds colorized tables of frequencies to highlight patterns of association, association graphs to visualize conditional independence and a variety of new or improved statistical tests for categorical data analysis.