Top 20 NuGet spelling Packages

Spelling correction & Fuzzy search: 1 million times faster through Symmetric Delete spelling correction algorithm
A port of Hunspell v1 for .NET, .NET Standard, and .NET Core.
ISO 3166 countries library, including: common Name, official Name, TLD,two and three letter country code, ISO numeric code, CIOC, currencies, callingCodes, capital, alternative spellings, region, subRegion, borders, is landlocked and area in square kilometers
A simple “one component per form” (or other container) solution for multi-lingual spell checking and correction in Windows Forms applications. Add the component to your project and drop it on a form, then call InitSpelling_AllTextBoxes at run time to include spell checking capabilities in all yo...
Zoople Text Spelling is spell checking DLL for .NET Framework and COM applications - Multi-lingual spell checking on Windows 8, 8.1 and Windows 10 - Checks single words, sentences, and paragraphs - Returns character positions, and spelling suggestions for each word checked - Requires no additional...
Either drag the RapidSpellDialog and RapidSpellAsYouType spelling controls into your XAML, or programmatically create in C# or VB.NET (and it really is just a few lines of code).
Either drag the RapidSpellDialog and RapidSpellAsYouType spelling controls into your form, or programmatically create in C# or VB.NET (and it really is just a few lines of code).
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...
Spellchekr is a basic framework for building simple spell checkers.
prowritingaid.com services CSharp API
A native .net core spellchecker. Compatible with .netcore 1.1, 2.0 and .net framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6.1, 4.6.2 and 4.7
This lightweight library is used to spell out numbers in positive integer 64 bit into spelled out numbers from 1 to 999,999,999,999,999 (Trillion). Currently, it only supports ID (Indonesia) and EN (English) languages.
Nequeo spelling Australia component
Nequeo spelling Canada component
Nequeo spelling France component
Nequeo spelling Germany component
Nequeo spelling Italy component
Nequeo spelling New Zealand component
Nequeo spelling Portugal component
Nequeo spelling Russia component