Model, View, Controller
 

Just wondering how many people, knowledgeable in programming or not are familiar with the model, view, controller style.
This is the most widely used style, though i'm sure it has other names.
Basically is seperates all UI code into view files, model (the code that could be used independant of the UI) into model files, and controller files to link the other two.
It makes sure no part of your code has access to something it shouldn't. Also limiting what the end user is able to change, ie a hacker.