I've got plenty of school books in this format, but they are nearly useless if I can't edit them in any fashion. There are two readers with this function (UltraCHM and BeyondCHM) but both are made look disreputable by their websites - it's not entirely clear whether they are freeware or demos or what (and something makes me think they are one and the same program - although I may just be paranoid :P)... hence why I haven't tried them, I don't really want to get keylogged.

Can anyone quell my fears of the above mentioned programs or offer help in any other way? :/