Baloo!

Agent Ransack is a tool for finding files and information on your hard drive fast and efficiently. When searching the contents of files Agent Ransack also displays the text found. Users can then quickly browse the results without having to separately open each file!

grepWin is a simple search and replace tool which can use PCRE regular expressions to search for strings of text within files. grepWin adds an entry to the shell context menu to easily search selected folders. The use of regular expressions allows for a very powerful search and replace.

AstroGrep is A Microsoft Windows GUI File Searching (grep) utility. Features include regular expressions, versatile printing options, stores most recent used paths and has a "context" feature which is very nice for looking at source code.

dnGrep allows you to search across files with easy-to-read results. Search through text files, Word documents, PDFs, and archives using text, regular expression, XPath, and phonetic queries. dnGrep includes search-and-replace, whole-file preview, right-click search in File Explorer, and much more.

Replace Text, formerly called BK ReplaceEm, is the free string-replacing utility for Windows.