The State Committee of the Russian Federation for Standardization and Metrology. The Russian commitee of stadards, originating from Soviet Union days and having a long and glorious history - well, as long and glorious as paper-writers can possibly have. Nowadays, they're the Russian voice in ISO and other international standards bodies.
Also, the name GOST is used in names of the standards they make (if you see "GOST" followed by a number, they made it) - not entirely different from other standards bodies.
They have a web page: http://www.gost.ru/
In cryptography circles, the name most often refers to GOST 28147-89, which is a block cipher. Its closest American equivalent would be DES, but there are large differences. It's a 64-bit block cipher with 256-bit key and 32 rounds.
For more information about GOST, see Applied Cryptography, 14.1, page 331 in 2nd ed.
Of course, there's the another aspect... as everyone knows, when the US Government approached IBM to develop an encryption system, they came up with EBCDIC. Likewise, the USSR government approached their computer scientists and they came up with KOI8... =)