Indy is an open source client/server communications library that supports TCP/UDP/RAW sockets, as well as over 100 higher level protocols including SMTP, POP3, IMAP, NNTP, HTTP, FTP, and many more. Indy is written in Delphi but is also available for C++Builder and FreePascal.
![Indy](https://cdn-ak-scissors.b.st-hatena.com/image/square/fd6a796e90db6f83c274f243c4e2b4f58a8f22fc/height=288;version=1;width=512/https%3A%2F%2Fwww.indyproject.org%2Fwp-content%2Fuploads%2F2018%2F01%2Fcropped-IndyLogo.gif)