Scheme is a multi-paraigm programming language. It is one of the two main dialects of Lisp and supports a number of programming paradigms but is best known for its support of functional programming. It was developed by Guy L. Steele and Gerald Jay Sussman in the 1970s. Scheme was introduced to the academic world via a series of papers now referred to as Sussman and Steele's Lambda Papers. There are two standards that define the Scheme language: the official IEEE standard, and a de facto standard called the Revisedn Report on the Algorithmic Language Scheme, nearly always abbreviated RnRS, where n is the number of the revision. The most widely implemented standard is R5RS, and on August 28, 2007, R6RS, the next major revision of the Scheme language was ratified, with about two thirds of the voters in favor of R6RS.