grep is an often used tool on linux. It's job is very simple, to find a string (or regular expression) in a group of files.

grepWin is a gui version and is a lifesaver if you have to use windows as part of your development environment. The best bits are

• Integrates with windows explorer. Search any folder by right clicking on it.
• Results behave just like a windows explorer folder. Right click on the files to edit from the results panel.
• Regular expression support. A feature compared to windows built in search.
• Search and replace. The tool goes further than grep and will do a search and replace over many files.