LearnOutLoud.com - LearnOutLoud.com is the web's largest resource for audio & video learning.
Tellico - Tellico is a KDE application for organizing your collections.
DigitalBook.io - Free audio books and eBooks. Search, browse, listen, read and download over 100,000 free audio books and eBooks.
Delicious Library - Delicious Library 3: Catalog your books, movies, music, software, toys, tools, electronics, & video games. Archive your life.
Downpour.com - Listen to high quality audiobooks instantly. Download audiobooks to your iPhone, Android, or other listening device. Find titles including best-sellers and new releases. Downpour, where content reigns.
Readerware Book Database - The easiest, fastest way to catalog your books, nothing else comes close.