A PDF annotator with room to think beside it. Highlights, notes and a canvas, around one page.

Most in-browser annotation is anchored to coordinates: the note is stored as a position on a rendered page. Change the zoom, open it on a laptop instead of a desktop, or let the viewer reflow, and the highlight ends up over the wrong words.

Here an annotation is anchored to the text it was made against, so it finds the same sentence at any zoom and on any screen. Select the words, write what you thought, and it stays on those words.

There are two different things people mean by annotating a document, and most tools only do one. One is marking up the page itself. The other is everything you write *about* the page, which usually has nowhere to go except a separate app.

Both live here. Sticky notes are rich text, in whatever paper colour, ink and size you want, grouped by the day you wrote them and filed against the document that prompted them. So the marginal note goes on the margin, and the paragraph you wrote working something out goes beside it rather than in another window.

Every document gets its own drawing board — a real canvas, not a pen tool over the page — and it opens beside the document rather than on top of it. That is the arrangement that matters if you are working through anything with a figure in it: you redraw the diagram while the original is still visible, which is a different activity from tracing over it, and it is the one that makes it stick.

It saves as you go. The document itself can be minimised into a floating window when you need the full width for the drawing.

The same workspace has a chat that has read the document end to end and answers only from its pages. Highlight any part of an answer to keep it as a note or turn it into a task — so the thing you learned and the thing you have to do about it are recorded where you were already working, not in a different app you will have to reconcile later.