Okay, first of all, there aren't any trainers or hex editors for Riven. You don't even have a character in Riven, much less any stats, skills, hit points,
or even an inventory you might conceivably want to edit. I don't really have any idea what people who email me asking for a "Riven character editor" are really
even looking for.
The only way to really cheat in this game is to look up the solution to a puzzle rather than figuring it out yourself--and frankly, if you're
going to do that, why would you play this clunky old puzzle-adventure classic in the first place? Take away the puzzles and Riven is nothing but a pretty,
exceedingly boring slideshow of some exotic island somewhere. You might as well look at Aunt Edith's photo albums of her trip to Sumatra.
Anyway, so there's not much cheat to be had on Riven, but if you need a puzzle solution or just want to learn more about this game, here are a few
good links for you:
My Riven Pages:
Riven Hints, with general gameplay information and suggestions.
The Non-Boring Guide to Riven Walkthrough, with detailed instructions of where to go next
at each point in the game to eliminate the tedium of excess travel, useless locations and time-wasting red herrings, but without spoiling any of the puzzles.
Riven Review, with a spoiler-free overview of the game for those considering playing.
Universal Hints System is a great place to get a spoiler for one specific puzzle you're stuck on without accidentally ruining any of the rest of the game--they have
their walkthrough uniquely structured to reveal only one hint at a time.