Please inspect one of my most recent submissions (http://www.gutenberg.org/ebooks/40867, in German, so the text won't distract), and tell me what I can improve here to guaranty better cross-browser functionality. The HTML is generated from TEI (except for the PG standard header and footer), and I can adjust the tools that generated it at will... (http://code.google.com/p/tei2html/), so that will immediately improve all my following submissions as well.
Starting by looking at a desktop browser: I try downsizing the default window, to see if there are any issues where some aspect of the design is "hardwired" to the assumption of display size and shape. I find immediately that the cover image isn't scaling nor centering correctly. As I downsize the margins appear to be excessive. This will prevent reading the HTML on small display devices which directly understand HTML. For example I open the HTML directly in my tablet, and the margins consume excessive screen real estate. Horizontal rules I would think were intended to be centered, but are showing up left-aligned. Chapter headings are left aligned, where I suspect in the original book and in common usage they should be centered. I see gesperrt, which I suspect will be troublesome on other platforms, we will see later. I also see use of margin page numbers, which will typically cause problems, again we will check this later. Next I try opening the EPUB in ADE. EPUB comes close to implementing most of HTML, and ADE is a pretty robust implementation of EPUB (with a few quirks) so this should not be a hard test: The PG boilerplate comes out "scrambled eggs" like always, but I don't see how one can blame a submitter for that which WW'ers provide "automagically." Rather, after how many years? maybe it's time for PG to get its act together. " Druckfehler und Berichtigungen" table doesn't work in EPUB. Gesperrt doesn't come through to epub, but you have italicized the entries anyway, so no great loss. Footnote numbering is showing up line-before the footnote. Some of the alignment in other tables are a bit off, but still for EPUB this looks like a good effort. Now onto a harder test, lets see how you are doing in mobi7 and mobi8. I open the mobi in Kindle Previewer, since these checks can be performed quickly there: Test mobi8 (which is close to being pure epub) by setting the previewer to Device="Kindle Fire" I see: Tables are scrambled. Footnote numbers are coming in again line-before. Epubmaker seems to have successfully killed your page numbers, which arguably is a good thing. Test mobi7 (which is a harder test) by setting the previewer to Device="Kindle" I see: "Karten" section doesn't format correctly. Tables don't format correctly, don't scale, and "run off the right edge of the display." Paragraphs all run together without indent or spacing. Horizontal rules on this machine do center, which I think was what you were trying to do in the first place. Rules seem to rendering unattractively long. Missing vertical white space after chapter headings. Also between chapter headings and subheadings. Also before these things. Next, let's test how much your code relies on unportable aspects which are being masked by having epubmaker "fix" these problems for you. This is interesting because we want PG books to be "write once read everywhere" which means that your HTML should be portable directly, and should not require epubmaker "fix-ups." We can test portability by directly opening the HTML in Kindle Previewer. This compiles the EPUB and the mobi7 and mobi8 directly, without given epubmaker a chance to try to cover for any mistakes: Mobi8 (epub, device="Kindle Fire"): The margins a WAY excessive, consuming most of the screen real estate. The cover image doesn't work, there is some kind of image format problem. TOC has a fixed vs. float formatting problem where "Seite" and page number "1" are trying to occupy the same place and are writing over each other. In general the TOC has fixed vs. float formatting problems causing overwrites. Tables don't work. Images inside tables don't work. The gesperrt came through correctly, which is a nice surprise. Mobi7 (Kindle Klassic, Device="Kindle"): "Inhalt" renders multiple times. "Karten" runs off the edges of the display. Tables don't display correctly. No indenting or spacing between paragraphs. "[Inhalt]" keeps showing up "everywhere" Footnote numbers render unattractively and intrusively in body text. No vertical whitespace before or after chapter headings. OK, now let's go back and take a look at the actual HTML code, and see if we can learn anything: Hmm, the CSS runs to about 700 lines of code! Cover size is being "hardwired." Out of curiosity, what happens if the 700 lines of CSS are removed? I recompile again directly using Kindle Previewer. The appearance doesn't change greatly, for better or for worse, but now at least "sensible" paragraph formatting is working both in mobi8 (epub) and mobi7. Still, I want to be clear that this book shows fewer formatting errors than most PG books I look at.