Smarty is a templating engine for PHP. Designers who are used to working with HTML files can work with Smarty templates, which are HTML files with simple tags while programmers work with the underlying PHP code. The Smarty engine brings the code and templates together. The result of all this is that designers can concentrate on designing, programmers can concentrate on programming, and they don't need to get in each others way so much. Even if you are developing a site on your own, Smarty is a powerful way to make your code clearer to you and others, as well as easier to debug and modify later.