Extension List/Categorization
PHP Manual

Membership

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

These extensions are bundled with PHP but in order to compile them, external libraries will be needed.

PECL Extensions

These extensions are available from » PECL. They may require external libraries. More PECL extensions exist but they are not documented in the PHP manual yet.


Extension List/Categorization
PHP Manual