calibre alternatives
Manages, converts, and syncs e-book libraries across dozens of formats and reading devices, with built-in viewing and editing tools
Free · Open
Builds and edits ebooks in the EPUB 2 and EPUB 3 formats, giving control over markup, metadata, styling, and table of contents
Ebook Editor·Desktop Publishing
Desktop
AlertCaution is advised.
Free · Open
A cross-platform WYSIWYG web and EPUB editor based on the Firefox rendering engine, supporting HTML5, CSS3, and SVG editing
Website Builder·Ebook Editor
Desktop
AlertCaution is advised.