The years of installing binaries that others put together along with the relevant Qt libraries are now a thing of the past. Sigil has entered Debian experimental and now is in unstable.
I like working on the transition from ocr'd text to opensource .html and even better .epubs of copyright expired text, especially Canadian eligible (life plus 50) sources as Distributed Proofreader Canada does in a joint effort and Faded Page serves up. But I often like to make that .epub nicer and not use Calibre markup. And sigil is what I like because in the end, I have more control of the outcome. Sigil tries to do one specific thing - convert .html or .xml formatted for .epub into finished .epubs whether it is to be for sale or for free.
The git of whence it comes
https://github.com/Sigil-Ebook/SigilSigil's web site
https://github.com/Sigil-Ebook/SigilSupport forum for Sigil is nestled next to Calibre at
http://www.mobileread.com/forums/forumdisplay.php?f=165A tip of the hat to Norbert Preining. "man sigil" is a bit light but the other documention should be sufficient
