https://www.intergofed.org/
The International Go Federation is a founding member of International Mind Sports Association and was granted full membership of SportAccord (ex GAISF) on 7th April 2006 at the 40th General Assembly in Seoul, Korea, a step which should help IGF members...
https://www.usgo.org/
Go is . . . ancient board game which takes simple elements: line and circle, black and white, stone and wood, combines them with simple rules and generates subtleties which have enthralled players for millennia. Go's appeal does not rest solely on its...
https://www.pandanet.co.jp/English/learning_go/learning_go_1.html
Go is perhaps the oldest board game in the world. The rules are very simple, and you can learn them in a few minutes - but they lead to a countless number of intriguing patterns and clever maneuvers. The following pages describe how the game is played...
https://senseis.xmp.net/
Sensei's Library is a collaborative web site about and around the game of Go (also called Igo, Weiqi, or Baduk). It is a repository, a discussion medium, it is the pot of Go(ld) at the end of the rainbow! SL is whatever you make of it.
http://sabaki.yichuanshen.de
An elegant Go board and SGF editor for a more civilized age.
https://gogameguru.com
Get commented pro games, articles, Go problems and advice to help you improve more quickly. Enjoy the latest Go news, professional games and more. Join over 10,000 people and get weekly updates.
http://senseis.xmp.net/?GoTeachingLadder
The Go Teaching Ladder is a site where you can have your own games reviewed. Includes many already commented games.
http://www.moyogo.com
Automatic, instant Go pattern expert & relational Go game database
http://gowrite.net
GOWrite is a full featured SGF viewer, editor and publishing tool for game of Go known in japanese go(囲碁), Chinese weichi(围棋), or Korean baduk(바둑). GOWrite is freeware.
http://gogrinder.sourceforge.net
GoGrinder is a Java program for practicing go problems. It uses problems in SGF format. 347 problems are included in the install, and thousands more are easily downloadable (pointers in the documentation).
http://www.godrago.net/en.htm
Browse and edit files, print and export, and play against GnuGo.
http://webpages.charter.net/suewilcox/Sector.htm
Sector Fights are battles over containment, be it of a potential territory or a weak group. Sector Fights happen throughout the opening and midgame and their results are crucial.