Internet Archive is a non-profit digital library offering free universal access to books, movies, music, & computer software as well as 514 billion archived web pages. It has many different components and projects and was started in 1996.
The Internet Archive Text Archive contains a wide range of fiction, popular books, children's books, historical texts and academic books. You can download free books and texts from here as PDF and eHub formats.
The Open Library is a project of the Internet Archive. The site seeks to include a web page database for every book ever published. It holds 23 million catalog records of books, in addition to the full texts of about 20,000,000 public domain books, which are fully readable and downloadable. Open Library is an open source project, with its source code freely available.
Internet Archive has over 38,000,000 available public domain books and texts. (September 2023)
All of the books and texts are full-text searchable. Anyone can search and view the ebooks and texts. Public domain books are downloadable via PDF and eHub formats.