if i were doing it as something intended for serious use, i'd definitely want to see how lippert did it. but the point of doing this (other than the whole rite-of-passage aspect of writing a z machine :)) is the challenge of designing and implementing it from scratch, and hopefully as cleanly and compactly as possible. if i read lippert's blog and he came up with an idea i didn't think of after i had already solved it some other, potentially worse way, i'd be delighted to see that it could be done better. if i see his solution to some piece that i haven't even implemented yet it would just tempt me to simply adopt his solution.