Curl ➰
cURL (pronounced "curl"), the command-line tool and library that can be used to send API requests, was created by Swedish programmer Daniel Stenberg in 1997.
Root: The 'cURL' name is short for client and URL.
On the cURL website, Stenberg writes: "The name is a play on 'Client for URLs', originally with URL spelled in uppercase to make it obvious it deals with URLs. The fact it can also be pronounced 'see URL' also helped, it works as an abbreviation for "Client URL Request Library" or why not the recursive version: "Curl URL Request Library"."
Stenberg estimates there are roughly ten billion installations of cURL running worldwide in 2020.
Sources: What is cURL?