Version 2.0 introduced the plugin architecture that is used for almost all the customizable functionality of Smarty. This includes: functions modifiers block functions compiler functions prefilters postfilters outputfilters resources inserts With the exception of resources, backwards compatibility with the old way of registering handler functions via register_* API is preserved. If you did not use the API but instead modified the class variables $custom_funcs, $custom_mods, and other ones directly, then you will need to adjust your scripts to either use the API or convert your custom functionality into plugins. &programmers.plugins.plugins-howto; &programmers.plugins.plugins-naming-conventions; &programmers.plugins.plugins-writing; &programmers.plugins.plugins-functions; &programmers.plugins.plugins-modifiers; &programmers.plugins.plugins-block-functions; &programmers.plugins.plugins-compiler-functions; &programmers.plugins.plugins-prefilters-postfilters; &programmers.plugins.plugins-outputfilters; &programmers.plugins.plugins-resources; &programmers.plugins.plugins-inserts;