Publicador
This program allows the criation and maintainance of sites. With this tool each page of your site belongs to a "class" of pages, this class have a template witch describes how it should be rendered. This allows the separation of content and presentation, making it trivial to change the appearance of an entire wite with easy, for instance.
But that is not all, the publisher uses the "template toolkit" witch allows automation of a lot usual tasks like creation of menus and link updating.
This program is made to run in an internal server and publish into a independent production server, so it will not imply n any impact in the existing infrastructure of your site.