Scute is a security device that implements the PKCS #11 interface for security tokens. Applications which know how to use the PKCS #11 interface to access security tokens for crytpographic operations can use Scute to access the OpenPGP smart card. An important example of such an application is the Firefox web browser by the Mozilla project, which uses the Mozilla Network Security Services library (NSS).
Scute itself does not include a driver for the smart card itself. Instead, it uses the GnuPG 2.0 framework to access the smart cards and associated data like certificates. Scute acts as the glue between the application and GnuPG 2.0.
Currently supported usages are client authentication over HTTPS with Firefox (allowing users to authenticate themselves to a remote web service without entering their log-in information), email signing with Thunderbird, and document signing with LibreOffice.