Sigil is a multi-platform EPUB ebook editor with the following features
* Online Sigil User's Guide, FAQ, and Wiki documentation
* Free and open source software under GPLv3
* Multi-platform: runs on Windows, Linux and Mac
* Full UTF-8 support
* Full EPUB 2 spec support
* Multiple Views: Book View, Code View and Split View
* WYSIWYG editing in Book View, supporting all XHTML documents under the OPS specification
* Complete control over directly editing EPUB syntax in Code View
* Table of Contents generator with multi-level heading support
* Metadata editor with full support for all possible metadata entries (more than 200) with full descriptions for each
* User interface translated into 15 languages
* Spell checking with default and user configurable dictionaries
* Full Regular Expression (PCRE) support for Find & Replace
* SVG support and basic XPGT support
* Supports import of EPUB and HTML files, images, style sheets, and fonts
* Documents can be validated for EPUB compliance with the integrated FlightCrew EPUB validator
* Embedded HTML Tidy: all imported files have their formatting corrected, and your editing can be optionally cleaned
* Native C++ application