So I recently got myself one U2F security key to experiment with all the services that support it. However I didn't go for the mainstream option (Yubikey) since most models are quite expensive for my budget.
The thing is, almost all the docs for the things I thought I was going to be able to do with the key (e.g. override the passphrase for my ssh-keys or login to my machine) that I've been able to find online are hosted in https://developers.yubico.com and seem to work only with Yubi models. This kind of makes me wonder if Yubico is the only de facto standard keeping up with security keys.
At the end of the day it seems I'm only gonna be able to use my key for U2F-related tasks (i.e. browser-based login). Well... I actually made some stuff work with Yubico's Pluggable Authentication Module in macOS by following this tutorial: https://nicluo.com/projects/secure-your-mac-with-yubico-u2f-fido/ - but I'm unable to find many docs about which extra options are out there.
I'm quite a noob when it comes to crypto-protocols and algorithms, but I wonder if there's a way to see what does my card support, what can I do with it and maybe some good platform-agnostic resources for starters. e.g. Would I be able to sign emails/commits with my key?