Pretty Good Privacy
Pretty Good Privacy is a widely used encryption protocol for E-mail. This non-proprietary protocol is provided by the OpenPGP Alliance. Although this has changes somewhat, it is still based on the protocol originally developed by Phil Zimmermann.
In 1997, the OpenPGP Working Group was formed in the Internet Engineering Task Force (IETF). It's purpose was to define this encryption standard that had been a proprietary product since 1991. By becoming an IETF Proposed Standard (RFC 4880), OpenPGP may be used by any company without paying licensing fees. In December 1997, PGP was acquired by Network Associates Inc (NAI). NAI continued to own and develop PGP products for commercial and freeware purposes until 2002. At this time, NAI discontinued development and sales of PGP, and sold the rights to a new company, PGP Corporation.
Meanwhile, having left NAI in January 2001, Zimmermann started the OpenPGP Alliance, and is currently engaged in other projects, some involving OpenPGP implementors, including PGP Corp. He owns a website which provides more information on his activities.