Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.
GNU Find Utilities - The GNU Find Utilities are the basic directory searching utilities of the GNU operating system.
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
NTFS-Search - This tool enables users to search their NTFS formatted harddrives within seconds.
Agent Ransack - Agent Ransack is a tool for finding files and information on your hard drive fast and efficiently.
fd - A simple, fast and user-friendly alternative to 'find'.