Top 20 NuGet core Packages

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Adyen Checkout Handler
Stock locations shipping provider
SpecsFor is another Behavior-Driven Development framework that focuses on ease of use for *developers* by minimizing testing friction. This is package simply forwards to SpecsFor.StructureMap for backwards compatibility.
Gemini is an application shell similar in concept to the Visual Studio Shell. It uses AvalonDock and has an MVVM architecture based on Caliburn Micro.
The MonoGame runtime for Windows using DirectX API's.
Common utilities for .NET applications
Common markdown classes for .NET applications
Extend is a set of .Net extension methods build as PCL or .Net40 DLL. Extend enhance the .Net framework by adding a bunch of methods to increase developer’s productivity.
A .Net Core Client implementation for Json Rpc v2 requests.
A core package for Medidata HMAC protocol implementation. This package contains the core functionality which used by the MAuth authentication protocol-specific components. This package also can be used standalone if you want to sign HTTP/HTTPS requests with Medidata MAuth keys using the .NET HttpCli...
PdfReport.Core is a code first reporting engine, which is built on top of the iTextSharp.LGPLv2.Core and EPPlus.Core libraries.
TWCore Framework. A multipurpose framework library for .net core
TWCore Framework. A multipurpose framework library for .net core
TWCore Framework. A multipurpose framework library for .net core
iTextSharp.LGPLv2.Core is an unofficial port of the last LGPL version of the iTextSharp (V4.1.6) to .NET Core.
An UNOFFICIAL port of the DocuSign C# Client to .NET Core. If not using .NET Core, it is recommended to use the original DocuSign.eSign package.
DalSoft.Hosting.BackgroundQueue is a very lightweight .NET Core replacement for HostingEnvironment.QueueBackgroundWorkItem using IHostedService
Splunk .Net Core ILogger Compatible Library
TWCore Framework. A multipurpose framework library for .net core