Sigil

Sigil is a free, open-source, multi-platform EPUB ebook editor designed to help users create and edit ebooks in EPUB format. Its intuitive interface allows for both WYSIWYG and code editing, providing flexibility and control over ebook formatting and design. The application supports advanced features such as EPUB 2 and EPUB 3 formatting, metadata management, table of contents generators, and spell checking, making it a comprehensive tool for both novice and experienced ebook creators.