[Pablo]

Those of us who use BD have seen the "html0" file format. When you are editing a book, it is saved in the Lastfile subdirectory in this format. You can also make your book in "BookDesigner format", and the output file has the "html0" extension, too.

Having a look at the file in Lastfile, I discovered that the "html0" file is in fact a normal html file (well, normal enough to be opened with IE or MS Word once you change the extension from html0 to html). On the contrary, the file generated when you make your ebook in bookdesigner format cannot be opened with IE or Word and looking with a text editor I only see garbage.

So there is a difference between these files, no matter the extension. The one in Lastfile is bigger, so maybe some compression is involved.

I started looking at this format when I read that HarryT generated his books using both BD and Calibre, in this way I could produce ePub output, which is not possible with BD only.