Although it had a lot of oddities and wasn't the world's most stable program, Ami Pro 3.1 for Windows had hands-down the easiest-to-use equation editor I've eve

Although it had a lot of oddities and wasn't the world's most stable program, Ami Pro 3.1 for Windows had hands-down the easiest-to-use equation editor I've ever used. I wasn't doing really complicated math stuff, but was a chem major and the ability to do superscript and subscript directly above one another made any isotope notation very simple.