Digital Currencies, Crypto-finance and Open Source (beyond Bitcoin)

This is a nice list; I haven't heard of most of these before. I was wondering, due to all the recent press about bitcoin, if there are any competing currencies for bitcoin, and this article helps answer that question. However, all of the resources listed seem to solve different problems than bitcoin. Several of them enable the user to create their own currency rather than provide a single new one. None of the systems/protocols/programs listed have all of the following features that bitcoin has:

1) Decentralized and solves the double-spending problem without a central server

2) Automatic and controlled production of new coins

3) The rules are governed by the software running on a majority of the computing power, and thus the rules can change if the majority of the software changes

So bitcoin is unique, but there these other tools may be complementary to bitcoin.

If you'll allow me to pull a quote from the article, I think it would be interesting to discuss. Satoshi said this in the thread where he was introducting Bitcoin at the Cryptography mailing list:

"I actually did this kind of backwards. I had to write all the code before I could convince myself that I could solve every problem, then I wrote the paper. I think I will be able to release the code sooner than I could write a detailed spec."

http://www.mail-archive.com/cryptography@metzdowd.com/msg099...

By the way, if you only want to look at one or two projects, Open Transactions and Ripple are the most interesting imho.

Liberty Dollar is listed under "failed". As far as I've ever heard, it was just a private currency based on gold and silver, not a cryptocurrency or anything similar.

Nice list.fairly accurate summaries.