cURL
cURL is a command-line tool and library for transferring data with URLs. Originally released in 1997 by Daniel Stenberg, cURL is the de facto standard tool used by developers for testing, automating, and scripting interactions with HTTP, HTTPS, FTP, and many other URL-based protocols. It ships in two primary forms - the curl command-line binary used directly in shells and scripts, and libcurl, a portable C library that powers data transfer features inside thousands of applications, operating systems, devices, and programming languages.
APIs
cURL Command Line Tool
The curl command-line tool transfers data to or from a server using URL syntax, supporting protocols including DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDA...
libcurl
libcurl is a free, easy-to-use, thread-safe, IPv6-compatible client-side URL transfer library written in C with a stable API and ABI. It supports the same broad set of protocols...