Top 20 NuGet threading Packages

Extensions for System.Threading.Tasks Includes extension methods to safely fire-and-forget a Task and/or a ValueTask Includes WeakEventManger which avoids memory leaks when events are not unsubscribed
Quartz Scheduling Framework for .NET
An easy and reliable way to perform fire-and-forget, delayed and recurring, long-running, short-running, CPU or I/O intensive tasks inside ASP.NET applications. No Windows Service / Task Scheduler required. Even ASP.NET is not required. Backed by Redis, SQL Server, SQL Azure or MSMQ. This is a .NET ...
An easy and reliable way to perform fire-and-forget, delayed and recurring, long-running, short-running, CPU or I/O intensive tasks inside ASP.NET applications. No Windows Service / Task Scheduler required. Even ASP.NET is not required. Backed by Redis, SQL Server, SQL Azure or MSMQ. This is a .NET ...
Quartz.NET Microsoft.Extensions.DependencyInjection integration; Quartz Scheduling Framework for .NET
Quartz.NET JSON Serialization Support; Quartz Scheduling Framework for .NET
MongoDB storage implementation for Hangfire (background job system for ASP.NET applications).
Quartz.NET Generic Host integration; Quartz Scheduling Framework for .NET
Quartz.NET Jobs; Quartz Scheduling Framework for .NET
Quartz.NET ASP.NET Core integration; Quartz Scheduling Framework for .NET
Quartz.NET Plugins; Quartz Scheduling Framework for .NET
CodeJam is a set of handy reusable .NET components that can simplify your daily work and save your time when you copy and paste your favorite helper methods and classes from one project to another.
Async synchronization primitives, async collections, TPL and dataflow extensions. The JoinableTaskFactory allows synchronously blocking the UI thread for async work. This package is applicable to any .NET application (not just Visual Studio).
Quartz.NET TimeZoneConverter integration https://github.com/mj1856/TimeZoneConverter; Quartz Scheduling Framework 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.
Use dotnet Web Workers Threads in Blazor
Static code analyzer to detect common mistakes or potential issues regarding threading and async coding.
Redistributable components for package 'PostSharp.Patterns.Threading'. This package should only be installed as a dependency. (This is not the package you are looking for).
Various classes related to Threading. This package was built from the source code at https://github.com/RockLib/RockLib.Threading/tree/d506424cbf98ca921c8d4d23d3ab07365d66e470
Use dotnet Web Workers Threads in Blazor