Pressbooks - Create books: print and ebooks
Sigil - Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.
Time Capsule - Transform your 2020 into a tiny, personalized book for free!
Jutoh - Epub editor, convertor and creator software for Mac and PC.
Papermine - Create stunning digital booklets.
calibre - Ebook manager, viewer & converter