Why Kerned

Kerning is the part of typography nobody is supposed to notice. It is the space between two particular letters, adjusted until the word reads as a word instead of a row of shapes. When it is right, you see the word. When it is wrong, you see the letters. That is the whole discipline, and it is a discipline of removal: you do not add anything to the page, you fit what is already there.

I named the app after the past tense on purpose. Kerned is a description of type that somebody has already taken care of. It does not promise features. It promises that the thing in front of you has been fitted.

The file is the product

Every markdown file I care about is a plain text file on disk. It is in a git repo, or a folder that syncs, or next to code. Other tools write to it: scripts, build steps, and increasingly the AI agents I work with all day, which produce markdown by the yard and read it back just as often.

So the first rule was written before any code: the file on disk is the only source of truth. Open a file, save it without touching anything, and git diff shows nothing. Change one character and the diff is one character. No normalising, no reflowing, no helpful cleanup of your line endings. If you keep a .md file that way, the tool has earned the right to edit it. If it cannot keep it that way, it is not an editor, it is an importer.

What happened to markdown editors

Somewhere in the last decade the category quietly stopped being about files. The good-looking apps want your notes inside their database, their sync, their tag system, their account. You can usually get markdown out again, but the file was never the thing they cared about; the library was. And the ones that do stay file-based tend to go the other way, into feature lists: plugins, graph views, a hundred settings panes, a community of people configuring the editor instead of writing.

I did not want either. I wanted a markdown to look like a document while you type, without the part where the document has to live inside a whole different architecture and system.

Simple typography is the argument

A well-set page is one where nothing can be removed. The typeface serves the text, the measure is comfortable to read, the leading gives the lines room, and then the designer stops. Restraint is not a lack of ambition; it is the ambition. Every good book you have read was set by someone who knew a hundred things they could do to the page and did four of them.

That is the standard I wanted for a markdown viewer. Headings look like headings, lists look like lists, tables fit the window, code sits in its own box, and the markdown syntax fades instead of vanishing, so you always know you are looking at plain text. Then stop. No sidebar of your life. No database. No network at all.

What Kerned refuses to do

• It will not keep your notes. They are your files, in your folders.
• It will not sync, phone home, or create an account for you.
• It will not reformat your markdown to its own taste.
• It will not become a second brain, a knowledge graph, or a task manager.
• It will not ship a preferences window with two hundred switches. How it looks was decided once, carefully, and that is the theme.

What it is for

Opening a markdown file and having it look the way it should. Editing it and knowing the file underneath is exactly what you meant. Having several open at once without any of them going anywhere. Reading a document an agent just wrote and being able to tell, at a glance, whether it is any good.

That is a small ambition. Kerning is a small ambition too. The whole craft fits in the gap between two letters, and it is the difference between a page you read and a page you fight.

Kerned is that gap, taken care of.

Paul Genberg, Genberg & Co · Download Kerned