What are some alternatives?
When comparing Helpie Knowledge Base Wiki Plugin and Wikibooks, you can also consider the following products
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
Khan Academy - Khan Academy offers online tools to help students learn about a variety of important school subjects. Tools include videos, practice exercises, and materials for instructors. Read more about Khan Academy.
DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
edX - Best Courses. Top Institutions. Learn anytime, anywhere.
AMuseWiki - Amusewiki is more than just a wiki engine, it’s also a powerful authoring, archiving and publishing platform.
Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies