Vanillacoin deserves a mention when it comes to cpu mining.
vanillacoin.netRead the whitepaper direct linkInteresting note:
On my dual core chromebook (running kde via crouton), miner uses 50% of cpu power at 210KH/s. on my i7 it uses 25% 700KH/s, but the KH/s doesn't seem to matter much anyways, as both wallets have received about the same amount of coins. Dev says this is part of the algo, to promote a fair distribution. The dev claims he is mining this coin with only 1 macbook at 330KH/s.
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NOTE: I WOULD NOT BUY THIS COIN. AGAIN, DO NOT BUY THIS COIN!!!!! Most of the code is still closed source!!
If you have fun mining coins (like me), and like what the dev is cooking, then point a cpu at it.
I am not the dev and sure as hell dont have the skills to code this coin.
The way I see it, this coin is really something cool. Read the whitepaper. Then again, the devs name is john-connor, and anytime someone throws a terminator reference his way, it goes over his head, he could just be the greatest most dedicated troll i've ever seen.
EDIT: TO CLARIFY TO NOT PUT ACTUAL MONEY INTO THIS COIN, JUST A BIT OF TIME AND CPU POWER IF IT INTERESTS YOU.