Is it portable?
How can you trust it, not to phone home?
I am loyal to putty. Wherever I work, there is my putty.
We have a close relationship for 15 years now!
Most customers don't have any SSH client in their enviromnent and do not allow to install anything. Portable putty doesn't care.
Yes, you can make it portable, and it's been around for at least one decade by a very well known company used by major corporations.