4
2
There's been dozens of alternate cryptocurrencies but I don't believe many of them did much other than find/replace some strings.
We see Bitcoin as made up of the blockchain and proof-of-work via hashing of the next block. Have there been any altcoins that drastically strayed from this recipe?
1
Ripple is in my opinion very interesting that uses a very different system which isn't based on the block chain nor the proof-of-work algorithm. Rather, it uses a quite different consensus algorithm outlined here: https://ripple.com/wiki/Consensus
The only problem is that there's very little research about this concept and I can't figure out how it works more in detail without an official publication of some sort. All I can say is that it's different from any altcoin because it's based on trusting nodes that behave honestly and distrusting the ones that don't:
If someone should be dishonest, the honest actors will notice them lying and can disregard their future attestations. That is, if you lie once, you have no gain as the network doesn't care and they won't care what you say in the future.
1 The "trust" in Ripple's UNL (unique node list) setup for servers isn't that you need to trust the validator to be honest, it's a much lower bar in that you just need to trust them to not collude with another validator on your UNL (i.e. to not be dishonest in the exact same way as someone else, and if you don't/can't trust them not to collude then you don't put them in your UNL).
4The example I sometimes use is the NSA, Al Qaeda, the government of North Korea, the Mossad, and Disney corporation. You probably don't particularly trust any of these groups. But they're very unlikely to collude against you. (I just use this to show that trusting not to collude is a lower level of trust than, say, trusting to provide accurate information.) – David Schwartz – 2014-05-13T19:34:39.573
0
Counterparty is not even an altcoin, it is entirely compatible with Bitcoin. In fact, BTC is a first class currency inside Counterparty, which provides a financial toolkit for a global market, betting, derivatives, contracts for difference, and more.
Counterparty actually runs on the Bitcoin blockchain, and can therefore be considered part of Bitcoin itself. It's like a symbiote that uses the unused data space in Bitcoin transactions to create a true free market for securities, derivatives, "coins", crowdfunding, and anything people can come up with..
The original question was primarily opinion-based and thus not suited for StackExchange (a better fit would have been a forum such as bitcointalk.org). I edited the title to be more suitable. – Meni Rosenfeld – 2014-05-13T12:18:53.163