It's a fantastic tool to do easily all boring text operations!
Heytools - JavaScript tools, AJAX tools and some fully server side tools.
GNU M4 - GNU M4 is an implementation of the m4 macro preprocessor.
NimbleText - NimbleText is a text manipulation and code generation tool available online or as a free download.
XMLStarlet - XMLStarlet Command Line XML Toolkit
TextPipe - Search and Replace, Find and Replace, Web Sites, Database Extracts, XML, CSV, Tab, mainframe COBOL data and more
xmllint - command line XML tool