What are some alternatives?
When comparing Grammarly and GNU Aspell, you can also consider the following products
Google for Education - Google for Education takes the cast analytical knowledge of Google and transforms it into a platform that educators can use to better communicate with their students in innovative ways.
Druide Antidote - Que vous rédigiez une lettre ou un courriel, cliquez sur un bouton et voyez s’ouvrir un des ouvrages de référence parmi les plus riches et les plus utiles jamais produits.
Technolutions Slate - Slate is an Ed Tech solution that provides outreach, travel management, online applications, and online reading.
ispell - Ispell is a program that helps you to correct spelling and typographical errors in a file.
Lockdown Browser - LockDown Browser prevents cheating during proctored online exams. Learn how it integrates with Blackboard Learn, Canvas, Brightspace, Moodle, and more.
Hunspell - Hunspell is the spell checker of LibreOffice, OpenOffice.