dnGREP - dnGrep allows you to search across files with easy-to-read results.
regexxer - regexxer is a nifty GUI search/replace tool featuring Perl-style regular expressions.
AstroGrep - AstroGrep is A Microsoft Windows GUI File Searching (grep) utility.
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, ...
grep - grep is a command-line utility for searching plain-text data sets for lines matching a regular...
Multi String Replacer - Replace multiple strings at once!