The Greppy application was designed to be a rewrite of the unix command grep in python. It has a GUI like a notepad.

When you start Greppy select the menu File->Open, choose a text file to grep,
insert a regular expression and wait for Greppy to work.

You can modify and save the results like in a normal text editor. This is still an alpha so only basic features are implemented.

Greppy should run flawlessy on Win32, Linux, Unix, MacOSX but it is surely of
more use on Win32 since all the other platform has grep bundled.