JR Group
East Japan Railway Company http://www.jreast.co.jp/e/
Hokkaido Railway Company http://www2.jrhokkaido.co.jp/global/index.html
Central Japan Railway Company http://english.jr-central.co.jp/index.html
West Japan Railway Company http://www.westjr.co.jp/english/global_top.html
Shikoku Railway Company http://www.jr-shikoku.co.jp (Japanese only)
Kyushu Railway Company http://www.jrkyushu.co.jp/english/index.html
Japan Freight Railway Company http://www.jrfreight.co.jp/english/index.html
Railway Technical Research Institute http://www.rtri.or.jp
Railway Information Systems Co., Ltd. http://www.jrs.co.jp/somu/english/