Top 20 NuGet check Packages

Wrapper for the Lob.com API. Send snail mail with this .NET API.
Classes to support a business logic layer or an API. Keep child-parent relationships in sync. Wrap a result with data along with a Successful flag and a list of messages. Keep business logic units separate, implementing ISideEffect. Check whether a list is dirty.
A library for bootstrapping microservices with support for actuator style endpoints.
ASPNetSpell - The Spell Checking library for Microsoft ASP.Net. This .Net Spellchecker supports MVC, C# and VB.Net. Features include: 
* A spellchecking library written in 100% pure .NET code. A complete user interface with plug-and-play support for ASP.Net web forms , AJAX and MVC Dictionari...
A simple way of exposing application health checks in .NET applications.
Preconditions provide convenience static methods that help to check that a method or a constructor is invoked with proper parameter or not. In other words it checks the pre-conditions.
An extension for MVC HtmlHelper class to create POSTable checkbox list on a view, based on the data passed from the view model, or defined locally.
WebApi integration for NotDeadYet.
Common tools to create check boxes for ASP.NET Core MVC applications
Health check functionality for .NET Core projects
A tool to verify binary compatibility of a set of .dll files.
NDepCheck is a tool that helps you to keep the (static) architecture of a .NET software clean.
MimeBank is a file-type checker for dotnet.
A library for bootstrapping microservices with support for actuator style endpoints. NO LONGER UPDATED see Dotnet.Microservice.Dnx instead
Provides component status evaluation to integrate with monitoring services
Provides EF Core connection status evaluation to integrate with monitoring services
Health check functionality for ASP.NET Mvc and Web Api projects
A Middleware for Health checks
VerioCheck Contact Validation and Identity Verification API
Type Check (type-check) binding library for Bridge.NET projects.