This add-in constructs Venn diagrams with either constant or proportional areas. The former accommodate up to five variables and the latter are limited only by the distribution of the counts corresponding to the variables.
The proportional-area diagrams call methods kindly provided by Lee Wilkinson and documented in his paper “Exact and Approximate Area-proportional Circular Venn and Euler Diagrams”, available at http://www.cs.uic.edu/~wilkinson/Publications/venneuler.pdfThe corresponding computations are performed in Java, so you must have Java installed on your machine to run them.
The input can be either a single table with 0-1 variables or multiple tables with lists of items. For details, click Add-Ins -> Venn Diagram -> Help after installing the add-in.
An example screenshot is below.
Update May 4, 2015: The add-in now picks up the format of the frequency variable in the display.
Update December 20, 2018: Fixes for Java on Mac and cN0[idx] error.