Differences between PHP3 and 4 Extensions

[RobAC]

Out of curiosity, what are the differences between vBulletin for PHP3 and PHP4 extensions??

[Kier]

Only the addition of '3' to all file extensions.

[RobAC]

Kier,

If vB for PHP3 extensions is installed, can it be upgraded for PHP 4 at a later date?

[Wayne Luke]

Yes... As long as your server supports the extension. If you wanted to you could change the code and your system so that the extension could be .vb.

It is just a simple naming convention that is only loosely followed.