PDF Search for Mac - Search documents using Artificial Intelligence
dtsearch - dtSearch - The Smart Choice for Text Retrieval since 1991.
FYI - Find your documents, like magic 🔮
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
Slash - A "productivity machine" that forces you to do tasks 1-by-1
SearchMyFiles - Alternative to the standard Search For Files And Folders module of Windows. Duplicates search is also supported.