The telnet client comes with MS Windows, Linux and macOS. The only platforms were you need to install some extra component are Android and iOS.

Many companies have been preventing its execution or removing the package by default for a number of years.

Also most linux containers do not ships with such binaries to save on img size and reduce vuln management overhead.

> to save on img size

    $ ls --human --size --dereference $(which telnet)
    144K /usr/bin/telnet

The point is not that this particular binary is huge, the point is that we tend to strip images of anything that is not useful for the actual application shipped. So we strip everything. Also: small things adds up. On AI prompt can be handled reasonably by a single machine, millions of concurrent ones involve huge datacenters and whole energy plants being restarted/built.

The point of reducing the amount of binaries shipped with the image is also to reduce the amount of CVEs/vulns in your reports that wouldn't be relevant for your app but woulld still be raised by their presence.

Telnet client is an optional feature in Windows that needs to be enabled/installed.

telnet hasn’t shipped with macOS since 10.12 Sierra, ten years ago.

Debian also isn’t shipping telnet in the base install since Debian 11.

Thanks, sounds like a recent development. I don't use macOS, but on other peoples macOS computer it was always there, even when they are not developers. But it could very well be that these computers are ten years old.

I mean technically MS Windows 10 is ten years old, but the big upgrade wave to 10 only happened like 4 years ago, which is quite recently. Maybe that is similar to macOS users, I don't know that.

Are you sure? I can't seem to find the Linux implementation anywhere in the repo https://github.com/search?q=repo%3Atorvalds%2Flinux%20telnet...

You are absolutely right: s|Linux|GNU/Linux|