Green Dam

Definition
Green Dam software is filtering software promulgated by the Chinese government that can block political and religious content normally associated with the Great Firewall of China, China's sophisticated national-level filtering system. It increased the reach of Internet censorship to the edges of the network, adding a new and powerful control mechanism to the existing filtering system.

Source

 * OpenNet Initiative, "China's Green Dam: The Implications of Government Control Encroaching on the Home PC" (full-text).