I just learned about a neat site from Karen Fasimpauer’s blog. She wrote about Wikibooks, which is collaboratively developing open source textbooks online. Wikibooks also has a section called Wikijunior, which is specifically creating online textbooks (that can also be printed-out) accessible to children.
I was particularly impressed by its section on Ancient Civilizations, which has some very well-written chapters and will be very helpful to students in my World History class next year. It seems accessible to Intermediate English Language Learners. I’ve placed the link on my World History page at the bottoms of both the First Civilized People and Greece and Rome sections.
I understand all the concerns raised about the information in Wikipedia and projects like Wikijunior. In my experience, though, they’ve been accurate and accessible to my students. For example, the Simple English Wiktionary is a great dictionary for English Language Learners. You can find this site on my English Themes For Beginners page under Dictionaries.