on Birds of a Feather Press site:

Book Indexing Software

Fiction authors are lucky that they only have to create a table of contents, but nonfiction authors need to help readers navigate their content by creating a table of contents and a robust index, and for this you’ll need to master book indexing software or find a freelancer to index your book for you.

If you use Microsoft Word, there’s a Mark Index option available, but as a Mac users I was dismayed to learn that I couldn’t use available alternatives for creating an Index, so I researched PC and Mac options for finding affordable book indexing software options, and sourced where to find reputable book indexers, and the average cost of indexing a book.