The MPEG site is at http://www.cselt.it/mpeg/.
A brief description of MPEG-1 can be found at
http://www.cselt.it/mpeg/standards/mpeg-1/.
A brief description of MPEG-2 can be found at
http://www.cselt.it/mpeg/standards/mpeg-2/.
A brief description of MPEG-4 can be found at
http://www.cselt.it/mpeg/standards/mpeg-4/.
The ISO site is at
http://www.iso.ch/.
Gr. 3 is called one minute facsimile because it is usually employed with a vertical resolution that is 1/2 the horizontal resolution.
More details on the steps that led to the establishment of MPEG can be found in Chiariglione, L.: “MPEG—From the conception of the idea to its effects”
(http://www.cselt.it/leonardo/paper/conftele99/conftele99.htm), ConfTele99, Sesimbra, 4/15/1999.
The MPEG-4 reference software can be purchased from sales@iso.ch or can be downloaded from
http://www.iso.ch/ittf/.
A brief description of MPEG-7 can be found at
http://www.cselt.it/mpeg/standards/mpeg-7/.
MPEG-21 will be suite of standards. The first part is a “Technical Report”, a document describing the scope of MPEG-21
(http://www.cselt.it/public/mpeg-21_pdtr.zipi). This is being balloted.
In the case of MPEG-4 this has been formulated as in
http://www.cselt.it/mpeg/public/mpeg-4_procedures.htm.