What is the best tool for editing,formatting and authoring?

[nomykhan]

Hello

We are a technical content publisher. We do have a lot of tables & images in our books.
We have been using MS Word to develop our content. The content was successfully published on Amazon both kindle and paperback. We do not have any formatting issues.
However, when we publish our ebooks in EPUB format to platforms like SMASHWORDS, publish drive - the format of the book gets disturbed. I understand that these platforms have their guidelines but it's getting very complex to follow the guidelines separately of each publisher.
I am looking for a content writing/editing/authoring tool that can make our life easy. Make sure that the content is published in the right formatting. Will calibre, sigil type tools solve my problem? What do the professional publishers/authors/editors use?

Please advise

[jaydax]

I format my books in MS Word using minimalistic styles. I then import a docx file into calibre and use the calibre tools to first create meta data and then convert the book to EPUB format. That can be previewed in calibre and edited in the calibre editor. Within the editor are various tools for tidying up Word HTML, deleting unneeded styles and CSS and embedding any special fonts needed. Calibre also has a bug check for the ebook produced. That's pretty effective but you'll need a knowledge of HTML and CSS to use it effectively. It does offer some auto-fixes though. Even after running a bug check, it's wise to run the file through an online epubcheck before submitting it to publishers. Incidentally Amazon is happy to accept an EPUB file as a source document. EPUB2 is normally fine but if you are publishing something complex at Apple then calibre will produce EPUB3 files.
I use calibre in preference to Sigil since calibre offers more tools and is updated more often.
Using MS Word > calibre > EPUB > Amazon KDP gets me better results than using Word > Amazon KDP.