He has written nine books, published in multiple languages. Basic Chess Openings is his most popular work, published in Hungarian, English, Italian, German and French. Since 2005 he has written a chess column in the Hungarian daily newspaper Népszabadság and from 2006 has presented a TV-program on Hungarian SPORT1 TV (SAKKK!).
As a chess trainer, he worked between 1983–1986 as a second of GM Zoltán Ribli, between 1980–1994 as one of the coaches of Zsuzsa Polgár and in 2005, was appointed a FIDE Senior Trainer (the highest trainer licence of FIDE).
From 2001 to 2005 he was the Professional Director of the Hungarian Chess Federation (HCF). He coached the Hungarian Men's Team for the 2002 Bled Chess Olympiad, guiding the team to the silver medal position. From 2005 to 2010 he was the Public Relations Director of the HCF.
- Gabor Kallai rating card at FIDE
- Gabor Kallai player profile and games at Chessgames.com