The Go variant with passive ko is now called Stoical Go. The rule itself will hereafter be referred to as "stoical ko". As I mentioned in the other thread, all known forced Go cycles are impossible in this variant.
I've posted it on Sensei's Library and programmed it for Zillions of Games as well. All odd-sized boards from 7x7 to 19x19 are included, as well as the option of placing neutral blocks to change the shape of the board.
Have fun.
