It's just a user account on
sdf.org, a "public access unix system".
Probably the site broke after a recent system reconfigure. The user ID
associated is "awk" so you could contact them like any other SDF user;
I'm reluctant to post an actual email address due to potential abuse.
As it happens I have an SDF account so I will try sending an message to
user "awk" in case they are unaware of their site's breakage.
Regarding accessing the information on that site, it looks like
archive.org has a recent snapshot:
https://web.archive.org/web/20221013152154/http://awk.freeshell.org/
The individual code snippets also appear to be available w/o formatting
via Gopher even though the gophermap files have issues; to access do the
following:
1) run this with a Gopher client like lynx(1):
ex. lynx gopher://
sdf.org/1/users/awk/index/
2) note the particular code snippet, i.e. "0Adler32Checksum", then
re-write the URL like so:
gopher://
sdf.org/0/users/awk/index/Adler32Checksum
Within lynx(1) you can then print the page(s) to plain text files or use
the -dump option to do a redirect.