We create eBooks, both ePub (Barnes and Noble / Sony / and Mobi (Amazon / Kindle). We build SQL/database driven websites and iApple and Android apps. If you have to transform data from one system to another our utility scripts do the work.
Single source publishing: using our custom designed Word macros and templates our clients create print-ready PDFs or eBooks from the same source. For many books, a Quark/InDesign expert is not economical. Because our system was built from the ground up, we continually modify it to address the new features of the latest eReaders.
All eBooks are essentially simple HTML files linked together. If you're reading this page on an Internet Browser you could read it in an eBook. Some eBook distributors, like Amazon/Kindle,require a table of contents that is written into plain vanilla HTML file. If you uncompressed a Kindle file and opened that HTML table of contents you would be able to view the whole book in any HTML browser without the abstract XML files discussed below.
eBook readers need to obtain information about the book which it can use to catalog and organize the books by title, author, etc.
Because each eBook reader is different, a standard XML file format has been agreed upon, in which general information about the book is referenced. The OPF file contains "metadata"; that is, data that explains other data (which most people don't think of data, but as the book itself). For example, the copyright date is metadata of the book. The book you read doesn't have to include the copyright date anywhere in the text, though it's important information for the catalog system.
Data will never be easy for most people. eBooks are simple on the inside, but wrapped in a layer of abstract gobbldygook on the outside. When you look at the list of your books on your reader you are looking at information pulled from the eBook's"manifest", specifically a XML formatted OPS file.
Once a reader has "read" the metadata it will use it to create a table of contents which it links to its controls (buttons,touch-screen, etc.) All eBooks come with a table of contents coded into a second XML file, with an NCX extention. The complexity of the XML OPS and NCX files is what prevents many people from creating their own eBooks from scratch. The OPS and NCX files are specific to eBooks.
In order to simplify moving the book from computer to computer all the files are compressed into a single file. The compression used is zip format.
Before a distributor sends a book to a device it may encrypt that file using DRM (digital rights technology).
The computer industry is forever oscillating between central control (like mainframes) and distributed computing (like laptops). It also goes back and forth from simplicity to complexity to simplicity. We try to protect our clients from getting abused by one of those extremes.