Marshall Breeding is an independent consultant, speaker, and author. He is the creator and editor of Library Technology Guides and the libraries.org online directory of libraries on the Web. His monthly column Systems Librarian appears in Computers in Libraries; he is the Editor for Library Technology Newsletter, published through Library Technology Guides. From 2002 through 2021 he was the editor and contributor for Smart Libraries Newsletter published by the American Library Association, and has authored the annual Library Systems Report published in American Libraries since 2014 and in Library Journal from 2002-2013. He has authored fourteen issues of ALA's Library Technology Reports, and has written many other articles and book chapters. Marshall has edited or authored eight books. He regularly teaches workshops and gives presentations at library conferences on a wide range of topics.

Marshall is a recipient of the LITA LITA/Library Hi Tech Award for Outstanding Communication for Continuing Education in Library and Information Science.

He is a frequent speaker at library conferences around the world, speaking on issues involving many aspects of library technology and the global library automation industry.