Antarctica doesn't have a government. Instead, it is governed by international agreement. As such, Antarctic governance is an example of international cooperation at a very rare scale.
The Antarctic Treaty was originally drafted in 1959 and ratified by the first countries in 1960. To date, 52 countries have signed the treaty.
The Scientific Committee on Antarctic Research (SCAR) actually predates the Antarctic Treaty, having been established in 1958 to formulate and coordinate Antarctic scientific research programmes. Scientific research is the main activity on the continent and surrounding seas.
Physical operations in Antarctica is coordinated through Council of Managers of National Antarctic Programs (COMNAP), founded in 1989. Antarctic tourism is also coordinated by the International Association of Antarctica Tour Operators (IAATO), founded in 1991.