Extension Categorization
PHP Manual

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Core Extensions

These are not actual extensions. They are part of the PHP core and cannot be left out of a PHP binary with compilation options.

Bundled Extensions

These extensions are bundled with PHP.

External Extensions

In order to compile these extensions, external libraries will be needed.

PECL Extensions

These extensions are available from » PECL. More PECL extensions exist but they are not documented in the PHP manual yet.


Extension Categorization
PHP Manual