Calibre is a free and open source ebook library management application, including options for syncing to devices and converting between a large number of formats. Calibre also has a built-in e-book editor for EPUB and AZW3 formats.

Scrivener is software for writing that includes virtual index cards, outlining, version control, import/export options, and scriptwriting features, and provides a management system for notes and documents plus support for document metadata.

It allows the creation of documents from sub documents, ebook (epub and Kindle/mobi) and TeX and LaTeX export as well as ODF, PDF and Microsoft Word exports.

A Linux version is in beta, and an iOS version is reportedly under development