Quote from: n0nce on February 25, 2022, 10:45:03 AM

Yeah, but do other full node programs exist? I don't think anything is widely used besides Bitcoin Core.

That's true. There are alternatives, but you hear very little discussion about them. Armory was mentioned in the past as one of them. Another one I heard about is Bitcoin Knots. The user cellard made a good list about some other clients in a post from 2018. I am quoting the part that mentions the Core alternatives:

Quote

Quote from: cellard on May 23, 2018, 04:14:23 PM

The ones I know are:

Bitcoin Knots: This is developed by Luke Dash Jr and has some experimental features that sometimes are added into the Core client: https://github.com/bitcoinknots/bitcoin
Libbitcoin: I think this one was founded by Amir Taaki: https://github.com/libbitcoin/libbitcoin
BTCD: This one doesn't have a wallet and is written in Go: https://github.com/btcsuite/btcd
~~BitcoinJ: Very old client from back in the day, I think it was started by Mike Hearn: https://github.com/bitcoinj/bitcoinj~~ (removed because not a full validating node)
Bitcore: Looks like Trezor uses this one, but also Bloq...: https://bitcore.io/
Bcoin: Some exchanges use this one like Bitwala: http://bcoin.io/
Gocoin: Written in Go: https://github.com/piotrnar/gocoin

Quote from: n0nce on February 25, 2022, 10:45:03 AM

A serious bug in Core would probably affect everyone, no matter if they use SPV clients or not - after all, those guys very much depend on full nodes.

I have no objections to this part. If most full nodes go down or suddenly become vulnerable, the entire network will be shaken and decentralization would take a serious hit.