Sigil - Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.
PDF 2 Epub - Free online converter which allows to make an Epub ebook out of any PDF document.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
Pressbooks - Create books: print and ebooks
SCRIBA Senato eBook Maker - Scriba eBook Maker is a project for building ebooks using contents already available in other...
Mockupea - Mockupea is an online tool for creating 3d book mockups with a lot of features.