The Internet Engineering Task Force (IETF) is an almost completely volunteer organization and standards body devoted to the evolution of Internet architecture and the smooth operation of the Internet. Anyone who has an interest can participate. A quote from Dave Clark in 1992 sums them up well: "We reject kings, presidents, and voting. We believe in rough consensus and running code."
Most Internet related standards were developed or are maintained by the IETF. Much of their work is done on mailing lists. The other important place work is done is at meetings which take place approximately every four months.
IETF standards are only such because people use them. They may issue a RFC (document describing a standard), but if no one uses it, it does not become a standard. One way standards are proposed by Working Groups. Working Groups are approved by the Internet Engineering Steering Group, often because a group of people interested in a topic have created a Birds Of a Feather Session and the Session decided to set up a Working Group. The other way that standards and technology development is done through the IETF is by individual effort. However, that may include the work of several people and/or companies.
A technology or standards proposal is first published as an Internet Draft which is a working document. It is discussed, revised, and republished based on the discussion. Once parties involved are satisfied, it is submitted to the IESG, which performs a technical and process review. If issues are found, it is returned to the originator with comments.
If it clears the IESG, an IETF wide Last Call is issued asking for comments. Again, if issues are found, comments are attached and it's returned to the originator(s). If no last issues are found, the Internet Draft is sent to the RFC Editor for publication as an RFC.
The meeting I attended where I learned all of this was a tutorial for newcomers to the IETF and its meetings. The thing that was most striking to me was the highly democratic nature of the organization and its process for developing technology and standards. Anyone can become involved, propose, write, or discuss virtually anything the IETF touches. I believe that this ensures that these smart people develop the best possible technology and standards.