yubikey-agent is a seamless ssh-agent for YubiKeys.

Keys and certificates for YubiKeys, written in Go

An SSH and GPG agent which you can use with your PIV hardware security device (e.g. a Yubikey).

yubicrypt - An easy to use public key encryption program for your YubiKey.

yubisigner - An easy to use file signing tool for your YubiKey.

YubiSigner provides a convenient way to sign and securely verify file signatures with Yubico YubiKey, utilizing an organization's PKI infrastructure.

yess enables splitting secrets into shares using a Yubikey-based threshold schema

privage is a terminal based password manager and general file encryption tool

library and cli tool for signing verifiable presentation using yubikey

pgs - An easy to use CLI tool to sign email or Usenet messages with your YubiKey.

Go Native cli for configuring secure keys.

HashiCorp Vault login with YubiKey piv certificate

Enable secure file signing and verification with YubiKey using a compact GUI, supporting multiple hash algorithms and international standards.