As explained on its website: Copyleft is a general method for making a program or other work free, and requiring all modified and extended versions of the program to be free as well.
"Booknology: The eBook (1971-2010)"
Marie Lebert
Launched at the same time, the website of Encyclopedia Universalis included 28,000 articles by 4,000 contributors, available for an annual subscription fee, with a number of articles also available for free.
"Booknology: The eBook (1971-2010)"
Marie Lebert
Then Stephen King created a website to self-publish his novel The Plant in episodes.
"Booknology: The eBook (1971-2010)"
Marie Lebert