<i>This is where emacs comes in. Emacs has several find and replace commands, by regex or by plain string, on a text selection, or entire file (buffer), or multiple files. The beauty is that it works all in a interactive way, with the option to do it in batch when you press a button.</i><p>Both Visual Studio and Eclipse have these features, I'm sure there are many, many other editors and IDEs that also have them. It's not exactly rocket science.<p>If you want to champion Emacs, you might want to point out the features that really are unique and unmatched, instead of common features that everyone else implemented 10 years ago. Yes, yes, Emacs did it 20 years ago. Woo.