SSH Secure Shell

Windows (Putty)

 putty.exe from  Putty-CAC, an improved version of  Putty-SC adds PKCS#11 support to putty, which the upstream version does not have. It works flawlessly with OpenSC PKCS#11 module. Using the  pageant.exe from Putty-CAC allows to use  WinSCP with smart cards as well.

Linux / Mac OS X (OpenSSH)

See wiki:OpenSSH for more information.

PuttyCard (deprecated)

PuTTYcard is another, independent implementation to add smart card support to putty. Read more about it here, and download the files from opensc-project.org contrib directory.