CardBackend is used at run time in 14 crates (of which 1 optionally). It is a direct run-time dependency in 6 crates. It's used only as a dev dependency in 1 crate.

Depender (with downloads and own rev deps) CardBackend version
450 13 openpgp-card ^0.2
380 9 card-backend-pcsc ^0.2
210 openpgp-card-tools ^0.2
2 openpgp-card-sequoia ^0.2
yubikey-management ^0.2
1 card-backend-scdc ^0.2