Changed Functions
Other changes to extensions
Migrating from PHP 5.5.x to PHP 5.6.x
PHP Manual
New Functions
GMP
gmp_root()
gmp_rootrem()
LDAP
ldap_escape()
OCI8
oci_get_implicit_resultset()
OpenSSL
openssl_x509_fingerprint()
Zip
ZipArchive::setPassword()
Changed Functions
Other changes to extensions
Migrating from PHP 5.5.x to PHP 5.6.x
PHP Manual