OpenSSL changes in PHP 5.6.x
New global constants
Migrating from PHP 5.5.x to PHP 5.6.x
PHP Manual

## Other changes to extensions

### OCI8

- Support for implicit result sets for Oracle Database 12c has been added via the new oci_get_implicit_resultset() function.
- Using oci_execute($s, OCI_NO_AUTO_COMMIT) for a SELECT no longer unnecessarily initiates an internal ROLLBACK during connection close.
- Added DTrace probes controlled by the --enable-dtrace configure option.
- oci_internal_debug() is now a no-op.
- The phpinfo() output format for OCI8 has changed.

### Zip

A --with-libzip configure option has been added to use a system libzip installation. libzip version 0.11 is required, with 0.11.2 or later recommended.

OpenSSL changes in PHP 5.6.x
New global constants
Migrating from PHP 5.5.x to PHP 5.6.x
PHP Manual