A recent RFC passed in favor of using a namespace for PHP extensions.
Overview for 'php-watch'
Beginner's guide to compile PHP from the source, on Ubuntu/Debian with up to date instructions for PHP 8 and up.
A list of special PHP functions that Zend Engine can inline and optimize.
OPCodes, the execution units the PHP's Virtual Machine executes, can be listed and inspected, to reveal performance and code structure caveats and improvements.
`git.php.net`, the Git server that hosted PHP source code was hacked, and contained a RCE backdoor. PHP source is now moved to GitHub.
PHP 8.1's release managers will be appointed soon, and PHP 8.1 GA release is currently scheduled for 25/Nov/2021