The World Bank provides comprehensive national data for developing countries around the world. The data includes such measures as GDP, population growth, CO2 emission levels, poverty ratio, life expectancy, and others.
The World Factbook provides information on the history, people, government, economy, geography, communications, transportation, military, and transnational issues for 267 world entities.
The World Health Organization Country Information webpage provides information and data on all countries that are members of the United Nations and World Health Organization. The data includes population statistics, information on national health systems, disease burden, and health profiles of each country.