Short for the 3rd Generation Partnership Project, 3GPP is a group of telecommunications organizations that was formed to design the standards for a global 3G wireless communications network. It was started by AT&T and Nortel Networks in the late 1990s, when both companies were developing wireless networks for transmitting IP (Internet Protocol) traffic.
They were eventually joined by other organizations, including British Telecom, France Telecom, Telecom Italia, NTT DoCoMo, Lucent, Ericsson, Motorola, and Nokia. In late 2008, the 3GPP announced the first standard for LTE networks, and they continue to design and standardize new wireless networking technologies to the present day.
See our 3GP page for information on file extensions with a .3gp or .3g2.