So is there a quick technical overview of Libra contrasting it with other well-known cryptocurrencies? For example, it has smart contracts ("Move" programming language), how do they differ from Ethereum smart contracts?

2/ Libra uses a "consensus protocol" rather than "proof-of-work", like Ripple. Is there a good resource that fully explores the tradeoffs here. I understand Bizantine Fault Tolerance, but I'm not sure I grok how it's use in cyrptocurrencies.

3/ Libra is currently permissioned, which means only the group's members can run nodes, unlike Bitcoin et al. which are permissionless, where anybody can run a node.

4/ This also applies to the "smart contracts". It seems like you can't actually write your own smart contract and submit it, but can only interact with smart contracts written by the consoritium members.

5/ Libra is a "stablecoin", which means that rather than being it's own currency, it's backed by an underlying currency. Only it's not, it's a "basket" of other currencies. But it's not even that, it's a basket of "securities" denominated in a range of foreign currencies.

6/ Among other things, it sounds like the LIbra foundation is free to debase their currency at any time, because there isn't actually a single thing it's fixed to, and that it's exchange rate can simply be voted up or down.

7/ They've announced 'fraud protection'. I don't know how this works, but the lack of it is the defining feature of Bitcoin -- that the overhead of fraud protection is the costly feature that prevents efficient electronic transactions.

8/ It means a payment isn't a payment, and isn't confirmed by "crypto", because the fraud protectors can retroactively undo the payment.

9/ Of course, Ethereum already proved that this is a lie anyway, as they forked their entire blockchain to undo the transactions where some friends fo theirs lost money due to fraud.

10/ The entire point of Bitcoin was a libertarian view of non-governance. It hasn't quite turned out that way, as "core" developers wield enormous influence. However, Library scraps all that with centralized governance, where whatever they say goes.

11/ Will Wikileaks be able to receive donations via Libra as they can with Bitcoin? How about neo-Nazi groups? or do they get censored the same way Facebook censors other content, or the way credit card companies censored donations to Wikileaks?

12/ Libra is very clear that anybody can create an address and send funds to it, so the answer is appears "no", that it won't be able to censor things. On the other hand, with their centralized governance, it appears this can change.

13/ Like all cryptocurencies (that I know about), an address is simply a public/private key pair that you can send money to at any point, without first having to register the address with the system. The address is a pseudonym to an anonymous owner.

14/ Probably a better "stablecoin" to compare Libra to would be Venezuela's "petro", which was promised to be based upon 1 petro = 1 barrel of oil, but which turned out to be fiction.

15/ Libra appears to not be a block "chain" but a "tree". It appears people can verify things without needing the entire ledger history available to them. I don't quite understand the details of this yet.