HID(R) Activclient(R) (formerly from ActivIdentity) is a smart card middleware application widely used in the US Government and Military. It can be used to enable support for Smart Card in Browsers, Email programs and other applications.
PIVKey is compatible with the US Government PIV standard, and will work with HID ActivClient.
ActivClient supports PIVKey (and other PIV cards) in Read Only mode. That is you can't use ActivClient to write certificates to the card, only to read and use certificates.
Activclient will not support the PIVKey X.509 Certificate for Card Authentication (9E Key). That is because with PIVKey this certificate is secure with the User PIN.
If you have ActivClient installed on the same computer as the PIVKey minidriver, you may experience problems with ActivClient taking over contol of the PIVKey, prohibiting writing to the PIVKey. We recommend you Uninstall Activclient software on computers where you have to write to PIVKey.