A BookIs Nota PDF.

Every serious book I have designed ended the same way. Months of work on hierarchy, rhythm, margins and typography. And then the whole thing was flattened into a PDF: in effect, a photograph of paper.

Look at what a PDF actually is. It is a set of instructions for a printer: put these marks at these coordinates. It is a magnificent piece of engineering, and it was never meant to know what a chapter is. To a PDF, a footnote is just small text near the bottom of a rectangle. Open one on a phone and you are pinching and scrolling across a page designed for a sheet of A4. Ask a machine to read it, and it has to guess where the sentences go.

The other common format, EPUB, makes the opposite trade. It keeps the structure and lets text reflow to any screen, which is very good for novels. But the designer's page is gone. The relationship of an image to a caption, the architecture of a spread, the deliberate silence of a margin: these are thrown away. For an art book, a textbook, an encyclopedia or a scholarly edition, that is a real loss.

We solved music. We solved video. Long-form knowledge still travels as a photograph of paper.

This is strange when you think about it. In the last thirty years we rebuilt how music and film move through the world. Books, the oldest and most serious container of human knowledge, have changed the least. Most of the world's digital reading still happens inside formats designed around a physical page or an early e-reader.

.bok is my attempt to work on that gap. It is a young format, and I want to state this plainly: it is at version one, it is used by my own tools, and no standards body has heard of it. The ambition to make it a format for the world is exactly that, an ambition. But a format has to start somewhere, and they usually start with someone annoyed by a specific problem.

A .bok file is a sealed container. Inside it there is a small manifest, readable by any tool, stating the format, its version, the title and the date. Next to it sits the document itself: the book held as structured data.

The important decision is what counts as the book. In a .bok document, a page is not a picture. It has text, objects and a place in a sequence. The file records the page format and margins, the number of columns, whether the book reads left to right or right to left, and the covers and the spine as designed objects in their own right, including the three lines of text a spine can carry. A book's physical body is part of its data.

That last point matters to me more than any feature. A spine is usually lost in digital publishing, along with the back cover. But a book is an object, and people love it as an object. So in .bok, the object survives.

Direction is a first-class property as well. Right-to-left is not a patch added later. This comes from where I work. Persian, Kurdish and Arabic readers have been second-class citizens of digital publishing since it began, with broken layouts and reversed page turns. In this format the direction of a book is declared at the root.

The goal is the top-right corner of that matrix: structure and design carried together. The machine can see that this is a chapter, and the human can see the page exactly as its designer intended it. Being machine-readable matters more every year. A book that an AI cannot read properly will be left out of the way people increasingly find and study things. A book that is structured data can be searched, translated, cited to the paragraph and read aloud, without anybody guessing where the sentences go.

In .bok, a spine and a back cover are data. The object survives.

A format is nothing without tools. A file nobody can make or open is a thought experiment. So around .bok I have built two instruments, in two separate projects, and it took a recent audit of my own folders to see clearly what they are.

BOK Studio is the workshop. It is a browser-based tool for designing books and multi-page publications. A guided flow first helps you define the identity of what you are making. Then comes the Masterpiece Creator: a full editor with front cover, back cover and spine, each with its own colours and images, a page-by-page canvas built on a serious rich-text engine, page sizes, margins, facing pages, headers and footers, and automatic pagination. It can export to EPUB and PDF as well as .bok. It is the part of the system where a book gets made.

eBOK is the reading room. It is a scholarly library and reader, built for very large multi-volume works: single and two-page spreads, side-by-side bilingual reading aligned by paragraph, a choice of paper-like themes, instant offline search, audio narration with the paragraph highlighted as it is read, one-click citations, a knowledge graph, and a pan-and-zoom atlas. It can bring in EPUB and PDF, and it keeps your library in the browser with nothing uploaded.

I will be honest about something. These two grew up separately, and they have started to drift. They share the same container and the same declared type. Their document structures are different. The studio describes a book's design. The reader describes its scholarship: tables of contents, series, editors, paragraphs. Both of them call themselves version one, and that is a problem I now have to fix.

A format without a shared specification is two formats with the same name.

The fix is clear. One specification, version two, held in one shared package, that carries the studio's design and the reader's structure together. The studio remains the place to make books. The reader becomes the place to live with them. And the format between them becomes a real contract. This is the unglamorous work that decides whether a format lives. I also owe it tests, and a public document that lets anyone else build a reader without asking my permission.

Let me describe what I want, in the terms of one reader.

A student in Sulaymaniyah opens a large history in her browser. She has no connection today, and it does not matter, because the file is on her device. The book opens as it was designed, on a real page, with its cover and its spine. She reads Persian on one side and English on the other, aligned paragraph by paragraph. She searches every volume in an instant. She taps a paragraph and it is read aloud. When she needs a citation, it is correct, to the page. She asks a question, and the answer points to a passage instead of inventing one.

None of this is a fantasy. Most of these pieces already work in my reader, in early form. What has been missing is the idea that they all belong to the book itself.

This changes the economics of knowledge as well. Publishing has always been an expensive craft, and for languages like Kurdish it has often been impossible. Designing, printing and distributing a serious book needs capital that most of our writers and institutions do not have. So I have a specific hope for BOK Studio: that a small Kurdish press, or a scholar with no press at all, can produce a book with the dignity of a major publisher, and put it in the hands of a reader anywhere, as a single file.

It also touches the question of who controls a book. A book you buy on most platforms is a licence to view it inside one company's application. If that company changes its mind, the book may vanish. A .bok file is yours. It sits on your drive. It opens offline. It can be passed to a friend, subject to whatever its author permits. That was how books worked for five hundred years, and I see no reason why being digital should have ended it.

For five hundred years a book belonged to its reader. Being digital should not have ended that.

I should mention what this requires of authors and rights holders, because a format is not a licence. The freedom to carry a file must sit alongside respect for the people who wrote it. Any serious publishing system has to handle permissions honestly, and that part of the work is still ahead of me.

Formats have a strange kind of immortality. A good one outlives its inventors, its companies and its first purpose. The codex, the bound book of pages, replaced the scroll in the first centuries of the common era, and we are still using it. The tools we build today for holding knowledge may matter for a long time.

That is why I am willing to spend years on something that has so few users today. I said in another essay that a format is a repeatable shape: that the second edition should not cost what the first one did. A format is the most compressed form of a system. It is a set of decisions made once, so that everybody after you can stop making them.

I also said that a project can be worth doing without being finishable. .bok is exactly that kind of project. It may never become a global standard, and most formats do not. If it stays a good way for a few thousand people to make and read beautiful, structured, right-to-left books, it will already have done something that the big platforms never bothered to do.

But I will admit to the larger hope. I think the next great reader of books will not be a person. Every question put to an AI is, in the end, answered from what humanity wrote down. How that writing is structured, attributed and preserved is about to matter more than it ever has. Knowledge held as a picture of paper will be misread. Knowledge held as honest structure, with its authors' names attached, stands a chance of being read correctly, by both kinds of reader.

So here is the claim, as simply as I can make it. A book is not a PDF. It is an object and a structure at once: a body you can love and a mind that can be searched. We have digital formats for the body, and we have digital formats for the mind. I want one that remembers they were always the same thing.