Rex Hesner is a jazz musician, writer, and cartoon critic living in San Francisco. He established Cartoon Companion, arguably the world’s first website dedicated to reviewing and rating single-panel cartoons. He and collaborator Phil Witte wrote weekly postings over a two-year period before attracting the attention of New Yorker cartoon editor Bob Mankoff. Migrating to Mankoff’s online cartoon treasure trove, CartoonStock, provided Rex and Phil with countless cartoons to feed their blog, Anatomy of a Cartoon.