I am working on a very similar type of system now and I have settled on HTML::Template (thanks to the advice of some fellow monks). Besides being relatively fast and simple, it allows you to filter a template before variables are replaced in case you need to do some extra style changes. Although, depending on your system, you could leave a placeholder for javascript and either "include" the file or build up your javascript as a string and replace the "var" with it. Another thing I am doing that might help is build your system as an object-oriented system with an abstract base class. Then you can override functions for specific uses. For example, you can override a default "OutputStyle" routine with a package that inherits from the base module if you need to show palm trees, snow, etc. If your derived class doesn't have its own specific "OutputStyle" routine, the user still gets the default output. Hope that helps.