Deepwater drilling well blowout can cause serious damages and huge losses. In order to reduce the effects of accidents, the industry has developed several emergency response systems (marine well containment systems). We introduce the recent developments of such systems after BP Macondo subsea well blowout occurring on April 20, 2010 in Gulf of Mexico. The system functions, elements and arrangement of 14 kinds of capping stacks built by 7 companies(organizations) are reviewed. Capping stack, a hardware utilized to contain the blowout well at or near the wellhead, is the center piece of the system. Finally, we also give some recommendation for research on emergency response techniques for deepwater well blowout.