It uses Kr5ddits to vote up or down posts. Kr5ddits are earned by modding posts and comments or having your own posts and comments voted up.
If you are a troll or whatever your Kr5ddit balance will be negative from being modded down and it anonymizes you to only post as anonymous until you get a positive Kr5ddit balance.
Using Bitcoin, you can buy more Kr5ddits. If you are positive in Kr5ddits you can sell them on the market.
You can vote up or down as much as you have in Kr5ddits and in 24 hours they refresh to do it again.
The owner Procasti is going to make an open source version called FreeK666 and I am learning how it works.
At this point in time, an "improvement" to Reddit might be something that makes Reddit obsolete all together, perhaps by making the upvote/downvote system seem old and archaic in comparison to something that provides similar, but more robust content promotion.
I've reported three images to reddit admins of naked people who claimed to be under 18, and reddit did nothing.