Sigil

Sigil is an open‑source editor focused on creating and editing EPUB‑format ebooks. It provides tools for assembling book content, managing metadata, and generating the required EPUB package structure, allowing authors and publishers to produce compliant digital publications without needing to work directly with low‑level files.

The application includes PageEdit, a companion WYSIWYG XHTML editor that lets users edit the underlying markup of EPUB chapters in a visual environment. This integration enables both code‑oriented and visual editing workflows, making it possible to fine‑tune layout, styling, and structure while preserving the EPUB specifications.

Designed for use on multiple operating systems, Sigil targets writers, editors, and developers who need a free, stable solution for ebook creation and maintenance. Its open‑source nature allows the community to inspect, modify, and extend the software as needed.