Top 20 NuGet Socket Packages

Transport model in DotNetty
General purpose codecs for DotNetty
Application handlers for DotNetty
Buffer management in DotNetty
Chilkat .NET Class Library (64-bit) for SSH/SFTP, FTP, POP3, SMTP, IMAP, SSL/TLS, Zip, REST, OAuth2, HTTP, RSA, XML DSig, Encryption, Compression, XML, Socket, XMP, HTML to XML, JSON, JWT, OAuth1, conversion, PKCS12/PFX, Java Keystore, ASN.1, PEM, ECC, Async, ...
DotNetty common routines
Chilkat .NET Core Class Library
ExchangeSharp is a C# API for working with various cryptocurrency exchanges. Web sockets are also supported for some exchanges.
MQTT codec for DotNetty
It's a .NET socket tool which can simplify the socket client developing. This difference between this package and SuperSocket.ClientEngine is it doesn't include the protocol resolving library.
Chilkat .NET Class Library (32-bit) for SSH/SFTP, FTP, POP3, SMTP, IMAP, SSL/TLS, Zip, REST, OAuth2, HTTP, RSA, XML DSig, Encryption, Compression, XML, Socket, XMP, HTML to XML, JSON, JWT, OAuth1, conversion, PKCS12/PFX, Java Keystore, ASN.1, PEM, ECC, Async, ...
This is Azure Relay .NET Standard client library for Hybrid Connections. For more information about Relay, see https://azure.microsoft.com/en-us/services/service-bus/. This package is only supported on Windows 8 / Windows Server 2012 and newer.
Socket PCL Xamarin Cross platform for iOS, Windows 10 (UWP) and Android
High performance, reactive TCP / UDP socket middleware for .NET
Chilkat Runtime Component for Universal Apps for SSH/SFTP, FTP, POP3, SMTP, IMAP, SSL/TLS, Zip, REST, HTTP, RSA, Encryption, XML DSig, WebSocket, Compression, XML, Socket, XMP, HTML to XML, JSON, JWT, conversion, PKCS12/PFX, Java Keystore, ASN.1, PEM, ECC, Async, ...
x2net is the reference port of x2 written in C# targeting universal .NET environments.
A C# TCP client used to connect to UniversalServer
Total IP SDK. Total IP is a brasilian company that supply digital PBX services. This SDK allows you to build custom applications using the Total IP API (HTTP, SOCKET and database).
Zyan is a framework that simplifies development of distributed applications for desktop and mobile platforms. With Zyan you can publish any .NET class for remote access over the network. Zyan is highly customizable and provides you with tools to build modular and plugable distributed applications.
Native socket library in C#