Top 20 NuGet concurrency Packages

Akka.NET Persistence journal and snapshot store backed by SQLite.
Dependency Injection (DI) TestKit support for Akka.NET
Akka.NET TestKit for SQL-based ADO.NET Persistence middleware
Testkit for Persistence actor support for Akka.NET
F# API support for Akka.NET
TestKit for writing tests for Akka.NET Persistance module.
TestKit for writing tests for Akka.NET Persistance module using xUnit
TestKit for Testing Distributed Akka.NET Applications
TestKit for writing tests for Akka.NET using xUnit.
Testkit for Reactive stream support for Akka.NET
Helper classes for combining the Akka.Remote.TestKit with Akka.Cluster
Ultra-fast distributed actors for .NET.
Adds a concept of thread safety to C# and VB so that most threading defects are detected at build-time or in a single-threaded test coverage. Includes a deadlock detection policy and thread dispatching aspects. An official PostSharp pattern library.
NLog logging adapter for Akka.NET.
Functional API for MSR Orleans. Server-side library.
Functional API for MSR Orleans. Core and client-side library.
Dependency injection support for Akka.NET
Unit testing kit for Orleankka. Allows to unit test actors in a full isolation.
Ultra-fast distributed actors for .NET.
A thread-safe hash-based set