*Comments!* — Select any passage and attach a threaded comment, perfect for marking up a document for a coding agent or a colleague. Comments live inside the Markdown file itself as standard footnotes, so they travel with the file and stay readable in any other tool. Replies, edits, and deletes are all supported. *Footnotes* — Mud now renders Markdown footnotes. Clicking a reference marker opens a popover with the footnote body rendered as Markdown, and Down mode highlights footnote definitions and markers. And more: * Hover over the document title in the toolbar to reveal the file proxy icon. * Toolbar button icons have tooltips. * The Changes bar and Find bar now sit side by side when bottom-centered.

* Quick Look previews — press Space on a Markdown file in the Finder to see it rendered with Mud's syntax highlighting, alerts, and themes. Also renders live in the column-view preview pane. * Document thumbnails — Markdown files in the Finder show a portrait thumbnail featuring the file's first heading, so you can scan a directory at a glance. * Markdown document icon — `.md` files carry a dedicated Mud icon when Mud is the default handler. * Background tab badge — when a document reloads in a tab that isn't focused, a small brown dot marks the tab as having fresh content. The dot clears when you focus the tab. * Preferences set by `defaults write …` now take effect without restarting the app. You can find a thorough guide to "setting preferences from the command line" in Help > HUMANS, including some hidden preferences. * Word-level diff markers inside indented code blocks line up more accurately with the code they annotate.

Major new feature in this release: Change Tracking! Keep the document open while you or your coding agent saves changes to it. Each change is clearly highlighted. You can rewind to earlier changesets in the same session. Accept the changes when you want to clear the highlights away. It's really simple, and it's a really effective way of collaborating on large documents with your AI agent.

Smarter file watching: manual reload (Cmd+R) re-establishes file monitoring after external changes, with automatic retry and backoff. Local images update instantly on reload. Copy Code button: hover over any fenced code block in Up mode to copy its contents with one click. Generate diagrams toggle: Mermaid rendering is now optional. Turn it on or off in Settings > Up Mode. DocC alert configurability: choose which alert blocks are styled in the new Markdown settings pane. Down mode improvements: restructured layout for better rendering and accessibility. Keyboard shortcuts: F3 and F4 as quick alternatives for sidebar and find. Many bug fixes and subtle refinements!

A detailed and nicely designed Settings window, support for GFM alerts and DocC asides, support for shortcodes — :+1: — and Mermaid diagrams, helpful instructions for command-line usage, and explanatory error pages when a document fails to open for some reason.