[Static]

It would be quite helpful to develop an add-on system. Currently, if the add-on requires you to change a file, it is usually done by replacing a file. With many add-ons, replacing a file might break other add-ons. Some sort of guidelines would be good, or a system should be developed.

I propose a folder to hold all of the add-ons, and an add-on manager in the backend to keep track of them. The main addon file should be called "main.php" or something like that, so that when the script searches for addons, it looks for only that file. Then, a function that retrieves an addon or the author simply provides the "include" code to input in a certain file. If an addon needs some sort of configuration, either a database for add-ons or a file generated by the addon should be added.

Code:

.                               "addon1/files_here.php"
                               /
             "includes/addons/" - for the frontend addons
            /                  \
           /                    "addon2/files_here.php"
"comments/" - comments directory
           \                          "addon3/files_here.php"
            \                        /
             "ADMIN/includes/addons/" - for the backend addons
                                     \
                                      "addon4/files_here.php"

I got a little confused while writing this, so if it's confusing, I don't blame you. Improvements are welcome and necessary.