The Editor is the drafting surface. It writes into the same document Compile formats, so there is no export step between a finished draft and a finished book, and it provides the controls that determine how much of the interface is visible while you write.
Focus Mode and Composition Mode
Focus Mode dims the page except the current paragraph. Composition Mode clears the interface entirely, leaving the text and the cursor. Both are toggles rather than separate documents, so switching between them does not interrupt the session or alter the manuscript.
Saving
Prose is saved continuously into the document Compile reads. There is no separate export of a draft. On the Mac, iPad and iPhone applications, the current text is additionally written to a local file before each save and deleted once the server acknowledges it, which limits the loss from a crash or a forced quit to a few seconds of work.
In-story documents
Letters, emails and text exchanges are formatted by the Editor rather than by manual indentation. A letter takes a dateline, salutation and signoff; an email takes From, To and Subject fields. The formatting is applied at compile time as well as on screen, so it survives into the EPUB and the PDF.
Codex tagging
Select a name in the prose to link it to its Codex entry. The link is stored against the text, so the connection persists through edits and appears in both directions: the scene lists what it references, and the entry lists where it appears.
Appearance
Paper color and texture, the background image and its transparency and darkening, the page width, the zoom level and the typeface are all set from the controls at the foot of the window. These settings are stored on the device rather than on the server, so they do not follow you between machines.