Top 20 NuGet extensibility Packages

Lightning fast MEF engine, supporting System.ComponentModel.Composition and System.Composition.
Provides the Common Composition bindings for MEF.
High-level, composable and testable APIs for working with IDEs.
An implementation of the Tcl scripting language.
The MEF attributes and runtime classes in the .NET Managed Extensibility Framework (MEF) that are used for imports and exports, and exception types, in a .NET Standard compliant NuGet package form, as found in the System.ComponentModel.Composition namespace.
A NuGet package which can be used to easily create item and project templates for Visual Studio.
Provides the Common Composition bindings for Windsor.
Provides the Common Composition bindings for Unity.
Portable component composition annotations, dependency injection framework agnostic. Automatically register your application components by convention with the most popular DI frameworks, while keeping your code container-agnostic.
An implementation of the Tcl scripting language.
Provides the Common Composition bindings for Autofac.
An implementation of the Tcl scripting language. This package contains the MSBuild tasks and PowerShell cmdlets that enable integration [with Eagle] as well as the command-line shell [for Eagle].
Provides the Common Composition bindings for Ninject.
Custom xUnit data attributes.
Reference assemblies for Visual Studio Project System Extensibility
An implementation of the Tcl scripting language. This package is built with options that make it more suitable for use with Mono. Features specific to Windows and/or the .NET Framework will be unavailable.
An implementation of the Tcl scripting language.
Provides custom types, helpers and extension methods for Visual Studio extensibility.
Extensibility library.
Visual Studio Project System Extensibility