LibreTexts is an ecosystem of connected tools that empower educators to create Open Educational Resources at scale.

Description

LibreTexts is the largest centralized open education project and platform online. Founded in 2008 at the University of California, Davis as the ChemWiki, the LibreTexts mission is to unite students, faculty and scholars in a cooperative effort to develop an easy-to-use online platform for the construction, customization, and dissemination of open educational resources (OER)

LibreTexts is composed of four distinct products 

• Robust textbook publishing system. The LibreTexts Libraries are the central platforms and consists of 18 topic-specific repositories that can host your OER textbooks. The Libraries house a suite of custom authoring tools, enabling educators to quickly create and remix digital textbooks and eLearning modules.
• ADAPT is a homework system. Create engaging and adaptive assessments from a shared question bank including over 200,000 elements.
• Commons and Conductor provide a gathering point for all of your authors to share, search, and remix OER developed and curated by your community.
• Interactive H5P Learning Object Repository - Browse the world’s largest open repository of H5P resources and you’re sure to find what you need. Featuring collaboration tools and curated collections and hubs, you can quickly narrow down the type of resource you need by domain and type. H5P is an open-source interactive media tool to provides authors with the tools to quickly create immersive activities, assessments, and games.

Here is a more in depth overview of LibreTexts products and mission.