Support Jefk

been active in computer chess for almost four decades. Lead developer of the chess opening program Bookbuilder (sold via a website for a few years, now open source).

https://sourceforge.net/projects/bookbuilder/

Donations will help us (me and BB programmer A.R. to to continue).

Also made chess gambit training program Chess Gambiteer, and a prototype for a handicap chess system (based on rating differences) also at sourceforge:

http://sourceforge.net/jcek

My chess book at www.lulu.com

https://www.lulu.com/shop/jef-kaan/better-chess-openings/paperback/product-1mw8r8qz.html

Kindle version at Amazon

https://www.amazon.com/Learning-Chess-Openings-intermediate-levels-ebook/dp/B00WKE1HJC