The name

Naming things is hard.

The tool was about uploading and downloading data specified with a URL. It
would show the data (by default). The user would “see” the URL perhaps and
“see” then spelled with the single letter ‘c’. It was also a client-side
program, a URL client. So ‘c’ for Client and URL: cURL.

Nothing more was needed so the name was selected and we never looked back
again.

Later on, someone suggested that curl could actually be a clever “recursive
acronym” (where the first letter in the acronym refers back to the same word):
“Curl URL Request Library”

While that is awesome, it was actually not the original thought. We sort of
wish we were that clever though…

There are and were other projects using the name curl in various ways, but we
were not aware of them by the time our curl came to be.

Pronunciation

Most of us pronounce “curl” with an initial k sound, just like the English
word curl. It rhymes with words like girl and earl. Merriam Webster has a
short WAV file to
help.

Confusions and mixups

Soon after curl was first created another “curl” appeared that makes a
programming language. That curl still exists.

Several libcurl bindings for various programming languages use the term “curl”
or “CURL” in part or completely to describe their bindings, so sometimes
you will find users talking about curl but targeting neither the command-line tool
nor the library that is made by this project.

As a verb

‘to curl something’ is sometimes used as a reference to use a non-browser tool
to download a file or resource from a URL.