Firstly thanks to all those who replied. I would like to clear the point that what I am making is not a CMS. I just want to make a php based web app that is scalable like drupal and has support for themes, modules, etc. I was looking for some pointers on the design aspect of a similar php - mysql based projects. How to design the database, what parts of code can be reused, how to make a project theme-able, module-able, how to design the filesystem layouts, how to make sure its secure, structures for admin area - user area, how to design the class and functions, how to design the page structures, etc ps : I have read both the books (esr, producing foss) - but they dont have any answers for what I am looking for. I hope this will make my question more clear :) Excuse me for my bad english.