regexxer - regexxer is a nifty GUI search/replace tool featuring Perl-style regular expressions.
grepWin - grepWin is a simple search and replace tool which can use PCRE regular expressions to search for...
dnGREP - dnGrep allows you to search across files with easy-to-read results.
DocFetcher - DocFetcher is a portable German/English open source desktop search application.
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, ...
Multi String Replacer - Replace multiple strings at once!