System Tables Data Dictionary Oracle PLSQL Tutorial

SQL>
SQL> SELECT object_name, object_type
  2  FROM   all_objects
  3  WHERE  owner = 'SYS'
  4  AND    object_type IN ('PACKAGE', 'PACKAGE BODY')
  5  and    rownum < 50
  6  ORDER BY object_name, object_type;
DBMS_ADVISOR              PACKAGE
DBMS_JAVA_TEST            PACKAGE
DBMS_JAVA_TEST            PACKAGE BODY
DBMS_LOB                  PACKAGE
DBMS_LOB                  PACKAGE BODY
DBMS_PICKLER              PACKAGE
DBMS_PICKLER              PACKAGE BODY
DBMS_REGISTRY             PACKAGE
DBMS_REGISTRY             PACKAGE BODY
DBMS_REGISTRY_SERVER      PACKAGE
DBMS_STANDARD             PACKAGE
DIANA                     PACKAGE
DIANA                     PACKAGE BODY
DIUTIL                    PACKAGE
DIUTIL                    PACKAGE BODY
PIDL                      PACKAGE
PIDL                      PACKAGE BODY
PLITBLM                   PACKAGE
STANDARD                  PACKAGE
STANDARD                  PACKAGE BODY
SYS_STUB_FOR_PURITY_ANALY PACKAGE
SIS
UTL_COMPRESS              PACKAGE
UTL_COMPRESS              PACKAGE BODY
UTL_ENCODE                PACKAGE
UTL_ENCODE                PACKAGE BODY
UTL_FILE                  PACKAGE
UTL_FILE                  PACKAGE BODY
UTL_GDK                   PACKAGE
UTL_GDK                   PACKAGE BODY
UTL_HTTP                  PACKAGE
UTL_HTTP                  PACKAGE BODY
UTL_I18N                  PACKAGE
UTL_I18N                  PACKAGE BODY
UTL_INADDR                PACKAGE
UTL_INADDR                PACKAGE BODY
UTL_LMS                   PACKAGE
UTL_LMS                   PACKAGE BODY
UTL_RAW                   PACKAGE
UTL_RAW                   PACKAGE BODY
UTL_SMTP                  PACKAGE
UTL_SMTP                  PACKAGE BODY
UTL_SYS_COMPRESS          PACKAGE
UTL_SYS_COMPRESS          PACKAGE BODY
UTL_TCP                   PACKAGE
UTL_TCP                   PACKAGE BODY
UTL_URL                   PACKAGE
UTL_URL                   PACKAGE BODY
XML_SCHEMA_NAME_PRESENT   PACKAGE
XML_SCHEMA_NAME_PRESENT   PACKAGE BODY
49 rows selected.
SQL>