Why use it?
One of Smartys primary design goals is to facilitate the separation of
application code from presentation. Typically, the application code contains
the business logic of your application, written and maintained in PHP code.
This code is maintained by programmers. The presentation is the way your
content is presented to the end user, which is written and maintained in
template files. The templates are maintained by template designers.
At its most basic function, the application code collects content, assigns it
to the template engine and displays it. The content might be something like
the headline, tagline, author and body of a newspaper article. The application
code has no concern how this content will be presented in the template. The
template designer is responsible for the presentation. They edit the template
files, adding markup and bringing it to completion. This typically involves
things like HTML tags, cascading style sheets and other tools provided by the
template engine.
Other 
