PHPVibe does not use a custom php framework or a MVC model, but it does use an easy to work with file system.
The main controler is index.php which will include all the next files.
index.php calls an component, a php file located in the /com folder and called com/com_{name}.php
which will call an template file like /tpl/{current theme}/{name}.php as final destination.
Why this?
Is a pretty simple to edit system.
No files are overwritten if you mix them in the same folder while coding (imagine having video.php and video.php in two different folders, one for component and one for theme output).
Example (single video page flow):
index.php (makes use of load.php which gathers all the libraries) -> com/com_video.php -> -> tpl/main/video.php