Sigil is free and open source software designed to create and edit digital books in the EPUB format. It can work with Windows, Mac and Linux . The interface is available in several languages, Spanish included. There are two modes of use: a simple one, basically to format the text and an advanced one that allows modifying the code of the file. It complies with the EPUB 2 standard , and is fully compliant with UTF-16 (a form of UCS and Unicode character encoding that uses variable-length symbols). On the other hand, Sigiloffers various display modes: book view, code view, and preview. It works with HTML and EPUB files , but also with images and style sheets. So that the user can verify that all the imported files are correct, it includes the HTML Tidy tool , which allows editing and cleaning the code. It allows checking the spelling of texts with various dictionaries , one of them by default and others configurable by the user. The metadata editor is fully compatible with more than two hundred entries, including full descriptions for each one. On the other hand, it can generate content indexeswith headings several levels deep. At any time, the user can validate the file to verify if it meets the specifications of the standard with an integrated FlightCrew validator for EPUB. Sigil also supports various functions outside the EPUB 2 standard , such as HTML 5 tags and audio and video files.
The developers advise that Sigil is an editor for EPUB 2 , which does not support all the features of the EPUB 3 version . However, it supports audio and video files, which is one of the main novelties of EPUB 3; in addition, it maintains the EPUB3 labels. In any case, the programmers anticipate that the next version of Sigil will be fully compatible with EPUB 3 , although, at the moment, there are few e-readers on the market that include all the functions of the third version.
The team behind the program also advises that, in some cases, although the digital book looks good in Sigil , the same may not happen with an electronic book reader, and vice versa. The reason is that although EPUB is a standard, each e-reader or reading program displays books in a slightly different way. Therefore, before completing the editing work, it is advisable to test the digital book on as many e-readers as possible.
A complete user guide available on their website, apart from various tutorials . There they explain, for example, how to convert the document to HTML (if the original is not in EPUB format ) so that it can be loaded into Sigil . They also describe how to add a cover and include book information such as author and title, as well as how to create an index. In addition, they detail a method to verify the validity of the electronic book with respect to the EPUB requirements . Another section contains various tips related to the styles and format of the book.
Sigil can be downloaded for free from here ; the developers welcome donations.