Over Gopher:

gopher://gopher.661.org/1/if-archive

Proxy:

http://portal.mozz.us

The previous URL over the proxy:

https://portal.mozz.us/gopher/gopher.661.org/1/if-archive

ZMachine games:

https://portal.mozz.us/gopher/mercury.661.org/1/if-archive/g...

Tristam Island and Calypso (and All Things Devour, plus Spiritwrak) can be fetched over git/github, they are libre games, so no issues there.

I can post links to the compiled ZMachine binaries if you want.