We are working on version seven of Putty for Mac and have made some good progress over the last couple months. We now have Pageant, plink, and puttygen working. So SSH and key authentication will be vastly improved over the current version.
Puttygen running on MacOS
plink running on MacOS
If you would like to support our efforts please go to our online store located here and make a purchase.
Putty for Mac 