Sigil 0.7.4

Sigil is a free and open source editor for the EPUB format. It is designed for easy, WYSIWYG editing of EPUB files and for converting other formats to EPUB. It also provides features for advanced users, like direct XHTML, CSS and XPGT editing. You can use it to add any of the metadata entries supported by the EPUB specification and create a hierarchical Table of Contents.

Sigil key features:

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