== Who wrote PHP?==
https://www.php.net/credits.php
== How do you upgrade? ==See the [https://www.php.net/manual/en/ migrating appendices in the manual] == Resource Sites ==
# Aidan Lister from Autstralia has a nice site online (source provided to make your own similar site) which lists many classes and PHP functions for doing routine things that you will inevitabably face in programming. Things like making a directory structure recursively, or checking the size of a directory and it's contents. http://aidanlister.com/
# Jeroen (John) Post created http://onlinephpfunctions.com/ which lets you play with PHP code in the browser, and specifically test that code with multiple versions of PHP.