sed
Sed: stream editor
Sed (streams editor) isn't really a true text editor or text processor. Instead, it is used to filter text, i.e., it takes text input and performs some operation (or set of operations) on it and outputs the modified text. Sed is typically used for extracting part of a file using pattern matching or substituting multiple occurances of a string within a file.
Version 1.4 is the fast, small sed originally distributed in the GNU toolkit and still distributed with Minix -- but it's still better for some uses (in particular, faster and less memory-intensive).
Utility
http://gnuwin32.sourceforge.net/packages/sed.htm