CDM is the acronym widely used to refer to the “Clean Development Mechanism”.
The Clean Development Mechanism is part of the “Kyoto Protocol To The United Nations Framework Convention On Climate Change” allowing industrialised countries with a greenhouse gas reduction commitment to invest in projects in developing countries, that result in GHG emissions reductions, to achieve some of their commitment targets in offsets from such projects.
Website: http://cdm.unfccc.int/index.html