[delphin]

Best two choices for long term archiving are EPUB (for most books) and PDFs (for the rare cases where rigid page layout and book formatting must be maintained).

Here's a rundown on each -

EPUB

EPUB is rapidly becoming the world standard for electronic book publication.

EPUB is HTML derived, so pretty much anything you could do in a browser window font and formatting wise is supported.

The main strength of EPUB is it's ability to 'reflow' seamlessly onto any display device's screen, just like a web page can be designed to provide a reasonably good view on ANY computer, even though computers have screens of varying shapes and resolutions.

Initially some epub formatted books were fairly basic, but the HTML 4 features supported by EPUB provides more than enough formatting goodies to handle really nice 'type set' quality books, and publishers are finally starting to pick up on this.

So EPUB books now commonly have professional typesetting features like justified text, chapter head graphics, drop caps, black and white and color figures and illustrations, indexes, tables of contents, as well as full support for both internal and external hypertext navigation.

For example, when I open a EPUB book from feedbooks.com they often include links to other titles by the same author. In web enabled EPUB readers like FBreader, the link will automatically download and display the linked ebook title just like a web browser.

These links currently don't go anywhere on my PRS-650, but internal links within a document navigate perfectly.

Another advantage of EPUB is the standard's simplicity. An EPUB book is nothing but a single ZIPPED archive of a folder containing a number of XML/HTML formatted text files (typically one per chapter), a HTML style CSS file to control formatting, an XML manifest file describing how all the pieces go together, plus any other required resources like JPG images and fonts.

If you rename an unencrypted .epub file to .zip you can unzip it and manually edit it's contents, then zip it back up.

Ever find a word misspelled in an Ebook? With a standard EPUB file, you can just go in and find the appropriate HTML file and fix it, then zip the thing right back up.

Though there are still some fans of Sony's native LRF format, as you can see from the above description, EPUB is now not only more widely used, but is also a lot more flexible.


PDF

Adobe's Portable Document Format has been around for many years now, and it has become a world wide standard for electronic publication.

As wonderful as EPUB is, there are some cases where a particular book may need to have more rigid control of formating for words and figures on a page, and for page-by-page layout within a book, than EPUB can provide.

PDF let's you control precisely, down to thousandths of an inch or fractions of a millimeter, just EXACTLY where something will appear on a page, and how that page will be formatted within the final document.

The main disadvantage of PDF formatted files is that they appear nicely formatted only when displayed on a certain sized screen or printed page that matches the original document size.

it is very difficult to 'reflow' PDF text so it will look right on a smaller screen; and though the PRS-350/650/950 Sony readers are one of the few ereaders that at least TRY to reflow PDF's the results are not always very good.

For example, let's consider the above paragraph, and take a look at how it will look with 'reflow' problems.

Let's imagine that this paragraph is turned into a PDF file for
a device with a with a right margin that falls here ---------- V

So now it looks like this -

it is very difficult to 'reflow' PDF text so it will look right on a
smaller screen; and though the PRS-350/650/950 Sony readers
are one of the few ereaders that at least TRY to reflow PDF's
the results are not always very good.

Heh, no problem, looks great, but the problem is that in creating the PDF, to define the right margin, we just added a bunch of 'hard returns' in the paragraph; one after "on a"; one after "readers"; one after "PDF's".

So now let's imagine that we want to move
the above PDF file onto a device with just a
little bit smaller screen.

So now the right margin is right here -------- V

Without PDF reflow, we get this -

it is very difficult to 'reflow' PDF text so it will
look right on a
smaller screen; and though the PRS-350/650/
950 Sony readers
are one of the few ereaders that at least TRY
to reflow PDF's
the results are not always very good.


See what happens? without some special processing, the formatting gets ripped to bits, because we have to deal with two sets of line breaks, the original hard returns, and the new line breaks caused by the smaller screen. If you have seen many ebook conversions, you have probably seen issues caused by these kinds of 'hard return' issues.

One advantage of the Sony PRS-350/650/950 readers, is that they will attempt to try to straighten out this mess. They can usually fix simple reflow problems like this pretty well, but it doesn't always work though. I have seen some PDF documents where trying to reflow just totally messed up the formatting.

Unlike PDFs, EPUBs are designed to reflow seemliness on any size screen and will never have these kinds of problems, but PDFs rigid layout has the advantage of haveing well defined page numbering and a closer correspondence between electronic and printed versions, so it's a trade-off.

So bottom line, PDFs have their uses, but it's best to stay with EPUB where possible and avoid formats like PDF, DOC, and RTF's which have a "fixed right margin", or embedded hard carriage returns, because they can cause endless formatting problems.