In “The UNIX Programming Environment” from 1984, mail is described like this:
“Sending mail to someone is straightforward. Suppose it is to go to the person with the login name nico.
$ mail nico
Now type in the text of the letter
on as many lines as you like…
After the last line of the letter
type a control-d.
ctl-d
$”

I tend to think in terms of 1 function that is meaningful for composability. The point in having small tools is that they can be combined in new ways, not just small programs for its own sake. To me it makes sense if you think of Unix itself as both the IDE and the system carrying out the purpose of the machine. We’ve gradually moved away from this though.

Ken actually uses Debian, at least he said so in an interview a couple of years ago.

People seem to think that those who choose permissive licences don’t know what they’re doing. Software can be a gift to the world with no strings attached. A company “taking” your code is never taking it away from you, you still have all the code you wrote. Some people want this. MIT is not an incomplete GPL, it has its own reasons.

For example, OpenBSD has as a project goal: “We want to make available source code that anyone can use for ANY PURPOSE, with no restrictions. We strive to make our software robust and secure, and encourage companies to use whichever pieces they want to.”