DocFetcher - DocFetcher is a portable German/English open source desktop search application.
dnGREP - dnGrep allows you to search across files with easy-to-read results.
Everything by Voidtools - Everything. Locate files and folders by name instantly. Everything. Small installation file. Clean and simple user interface.
grepWin - grepWin is a simple search and replace tool which can use PCRE regular expressions to search for...
Recoll - Recoll is a desktop full-text search tool. Recoll finds keywords inside documents as well as file names.
PowerGREP - Quickly search through large numbers of files on your PC or network using powerful text patterns to find exactly the information you want. Search and replace with plain text or regular expressions to maintain web sites, source code, reports, ...