Any editor worth its salt has some provision for text snippet expansion. TextMate, Vim, and Sublime Text 2 all have this capability and Emacs is certainly no exception. If you’re not familiar with the concept of snippets, the basic idea involves defining a keyword, which when followed with some trigger (keyboard shortcut or menu option), replaces that keyword with some predefined text. This functionality is a great boost to productivity as it prevents the developer from having to manually type potentially hundreds or thousands of lines of relatively boilerplate code.