I am looking to develop an Application in such a way that I can have an API for it making additional module integration into the software seamless. For example: I really love wordpress and how the plugins integrate well with the application. I have developed many applications and have a general knowledge of the process but its not really that structured. I am looking to read a well written tutorial that will put everything together. Has anyone encountered such a tutorial? If so please send me the link. I appreciate your help.