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Ebooks (or e-books, for electronic books) are just books, but made for the Information Age. So, they are not more electronic than they are virtual, or computer, or paperless books. More essentially, they are the terminal point of an evolutionary process which also includes the so-called desktop publishing, where classic typography means were gradually substituted with computational ones (not electronic, please, just computational). At the end of the process, also the final results of the book-production process become immaterial.

Being immaterial, an ebook is in principle free from the constraints of the paper-based version: however, human legacy – like the habits built up in half millennium of printed books (and several millennium of written ones) – brings about some desired/expected properties that do not strictly depend on the nature of ebooks – like the page-based structure super-imposed on the sequential structure of a text.

New properties, of course, become available and even desirable: 

  • Being immaterial, ebooks can in principle be reproduced indefinitely, at only the expense of computational resources. So, producing one copy or two millions copies of the same book has essentially the same cost. No copy needs to be produced before it is sold, no book copy is going to remain unsold on any bookshelf. Also, the notion of out-of-print book is obsolete, for ebooks: any publisher can reproduce instantly any of its ebook to respond to a reader request.
  • The digital form of ebooks makes them storable in computational devices, so they can be stored in computer memories, or cloud-based storage. So, unlike paper-based books, they are potentially indestructible, and can easily exist unaffected by the passing of time. Also, they can be passed from one digital device to another, and can be stored in portable computers, tablet, and smart devices, where they occupy quite limited storage resourtces: as a result, any bookworm can in principle fill its portable device with an almost unlimited number of ebooks, and have them always at hand.
  • In the same way as books though online services like Amazon, B&N or IBS, ebooks can be sold via Internet: unlike books, however, they can be delivered via Internet, immediately after the purchase. So, the same day a new book is released, or when the desire of a given available book arises, the book can be ready to be read in just minutes, or even seconds. 
  • Their digital form also promotes new forms for old habits, and even brand-new uses. Among the former, digital annotations and bookmarks: no more need for permanent marker signs, pencil notes, paper bookmarks. Any point of the text of the ebook can be added a digital note to record a reader's thought, a digital marker working as a bookmark, which can be left or removed at a will in any moment. Also, touch interfaces are quite perfect to reproduce the classical reading experience: a radar can pass through page by a simple touch of his finger. Among the latter, third millennium things like meta-data and text saving/sharing. Meta-data can be freely added to provide information about an ebook, which can help classifying, grouping, retrieving information about the ebook in a digital library – either personal or not. Portions of the (digital) text of an ebook can be selected by a reader and saved for further use, or shared with friends through the web – like, through social networks. Dictionaries, vocabularies, thesauri can be easily integrated so that for instance a reader can select a word he does not fully understand, and immediately access the same word in a dictionary, without really interrupting reading.
  • Being no longer bound to the paper form, new forms of books can be in principle emerge: for instance, with no need of pages, with multimedia capabilities, or integrated with web resources. We are still watching just the beginning of the story: in some sense, it's Gutenberg's time again.

In the overall, one may surely miss fascinating and romantic situations like looking for a rare text in a peripheral street market, sniffing the smell of a new paper book, or feeling the reassuring weight of your preferred books in your bag when starting for a long travel. However, some of the advantages of ebooks – in particular, when looking your wooden home library already more than full, or when you have to choose which books to bring with you among the thirty-five you would possibly like to read when travelling around – are undeniable. There are already several nice things that you can do with an ebook — and you cannot with a book. Even though things will just improve over time under that aspect, cost is definitely among the benefits of ebooks right now. 

So, ebooks are now among us, and this is definitely good news for any honest bookworm.

[See ebooks on Wikipedia]




Standards & formats

Sharing ebooks among different devices of diverse sorts from distinct vendors requires shared formats. The possibility of shared formats to spread widely and to survive over time is bound to the availability of standards for shared ebook formats. While a single standard would in principle simplify reader's life, a limited number of competing standards have the chance of promoting both the provision of different features and the test of new properties.

The most meaningful formats for ebooks today are 


PDF (Portable Document Format) is not a specific format for ebooks, but is instead born generically for electronic documents. PDF is born for having documents that retain their form whether they are read onscreen by any computational device (computers, tablets, smartphones) or they are printed on any sort of printer. 

A PDF document can contain text and pictures in almost any format: so, pages are typically recorded in textual format (then, the text can be searched), but sometimes they can also contain pages as pictures – as in the case of scanned documents, where the textual form is not directly available, and so not searchable. Nowadays, scanned documents are typically either made textual via OCR techniques, or distributed in DjVu form.
Defined by Adobe Systems, PDF is now an ISO standard. As such, it can be typically opened and read upon almost any modern computational device – obviously including tablets and smartphones.

[See PDF on Wikipedia]


The EPUB format is an open standard for ebooks defined by the International Digital Publishing Forum (IDPF). This is the de facto standard for ebooks, at least for those where the text is more important than the pagination. All ebook readers can read and display the EPUB format.

Being unconcerned with pagination, EPUB is the best choice for ebooks to be read on a wide range of different devices, where screen size and resolution may largely vary. In fact, ebook readers can let human readers choose the font size and kind, the page format (two-pages, one-page), and accordingly adapt to the screen in use.

By the way, EPUB is my format of choice for ebooks, whenever PDF is not necessary.

[See EPUB onWikipedia]

AZW & Mobipocket

These are essential two different Amazon formats for ebooks, with different DRM schemes. While Mobipocket is an old format (and the corresponding company is Amazon-owned), AZW is basically the Amazon format for Kindle, the Amazon ebook reader. 

This format does not add much to the EPUB platform, and exists almost only for bounding readers to the Kindle/Amazon platform, and to DRM-protect ebooks. This is why I use this format only when strictly necessary. There, my only real interest is removing DRM from Kindle ebooks, translating them into the standard EPUB format, and so read them in the way I prefer. Don't tell me this is illegal: I legally buy ebooks from Amazon, then they are mine to read them with any device I like, in whatever format I like. Amazon will not rule my life as an bookworm.

[See Amazon Kindle on Wikipedia]


DjVu is a format specialised for storing scanned documents, so that their digital form is a sequence of images rather than a textual one. Old books and documents that cannot be easily reconstructed in their textual form can be first of all scanned and made available in DjVu format. This format is not so widely recognised, but there are dedicated readers for many platforms, which can also translate DjVu documents into PDF ones – typically heavier, but easily read everywhere.

[See DjVu on Wikipedia]


For a comparison on ebook formats, one may read the following articles:


While Adobe Acrobat, Apple Preview ("Anteprima", in Italian) and other similar beasts are the typical way that everybody uses for PDF documents and ebooks, finding the right tool for handling (storing, reading, converting) ebooks is a little trickier matter. In the following, I mean to maintain a list of ebook related software packages and apps that could be of use managing ebooks on various sorts of devices. I will for now forget about dedicated eReaders, since I have no interest for now in specialised devices.


Calibre is currently the most versatile and all-powerful tool in the list. It handles almost all the ebooks formats (some problems with DjVu), the conversions among them, metadata research and modification, libraries, and also helps governing handheld devices, like tablet and smartphones, keeping your ebook libraries dutifully synchronised. While it is not actually a nice piece of software from an interface and aesthetic viewpoint, I recommend giving it a try before anything else.

Calibre is available for Windows, Mac OS X and Linux platforms.

[See Calibre on Wikipedia]

Amazon Kindle

Amazon Kindle...

[See Amazon Kindle on Wikipedia]

Apple iBooks


B&N Nook


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