There are 2 repositories under nntp topic.
Laravel based usenet indexer
A usable and IPv6-ready Usenet-server (NNTP daemon). It is portable (Linux/*BSD/*nix), supports AUTHINFO authentication, contains ACL as well as role based ACL and provides "invisible" newsgroups. It can run on MySQL and SQLite backends.
No-dependency, single file NNTP server library for developing modern, rfc3977-compliant (bridge) NNTP servers.
Client for communicating with servers throught the Network News Transfer Protocol (NNTP) protocol.
A .NET implementation of the NNTP RFC 3977 and IMAP RFC 3501 to create a communication server in C#
Download/grab binary posts from NNTP (Usenet) servers using Node.js
A News Reader as a webapp', bundled with a system for frequent checks of news, and a notifier system using mails, push notifications & pushbullet. Android and iOS apps available!
HTML2POP3 is a virtual POP3, SMTP and NNTP server
Experimental command-line NNTP downloader with on-the-fly Yenc decoding
A .NET Core NNTP client library to access Usenet newsgroups