Apps similar to YubiKey PIV Manager include Pkcs11Admin, which is free and open source. Other options are OpenSC. Between them they cover Mac, Windows and Linux.
Pkcs11Admin is an open-source GUI tool for administration of PKCS#11 enabled devices (smartcards, HSMs etc.) which runs under .NET 4.5 on MS Windows and under Mono 3.X on Linux and Mac OS X.
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OpenSC provides a set of libraries and utilities to work with smart cards. Mainly on cards that support cryptographic operations, and facilitate their use in security applications such as authentication, mail encryption and digital signatures.
