In World Game Review, issue 13, Michael Keller describes this variant, which has been invented by Kevin Maroney.
The variant was described in the context of Zillions Of Games, a (not yet marketed) program that one can learn to play new abstract board games. Michael Keller wrote a rules file for Hecatomb for this program, and the program won the first game it played on August 1, 1997 against Michael.
The game is played by two players on a board of 8 by 8 squares. Each player has 32 pieces: 31 queens and one king. The kings are positioned in the opening setup on e1 (for white) and e8 (for black); the other squares each contain a queen: a white one on each square (except e1) of the first four rows, and a black one on each square (except e8) of the last four rows.
Apart from this particular opening setup, the game is played following all applicable rules of chess.