Guidelines for Modular/Extensible Code

[eluser]Deep Arora[/eluser]
I understand that, but what I fail to undertand is the link between these custom plugins and libraries and core application.

I mean, lets say I have a application, now I want application to know automatically that some new plugin is written and saved in plugins folder and then it shows that plugin as pending in screen. Once admin enables the plugin, it gets installed and stars working..something like EE or joomla.