Midder

A native macOS Markdown reader for people who just want to open and read notes without adopting a vault model. No lock-in - open any .md file directly via Finder, Cmd+O, or drag-and-drop.

Rendering is pure AppKit TextKit (NSTextView/NSAttributedString), not a web view - with one deliberate exception: Mermaid diagrams are rasterized through a single isolated, offscreen WKWebView, since Mermaid’s layout engine has no native AppKit equivalent worth reimplementing. It loads no network content and the rest of the app never touches WebKit.

Features

• Clean native rendering of headings, lists, tables, blockquotes, and code blocks
• LaTeX math, both inline and block, rendered natively
• Syntax-highlighted code blocks
• Mermaid diagrams (opt-in, since it’s the app’s one WebView dependency)
• Click-to-toggle task list checkboxes that save straight back to the file
• Wiki-links ([[name]], [[name|alias]]) that open sibling files in a new window
• Styled YAML frontmatter display instead of raw text
• Heading outline sidebar for quick navigation
• Live-reload when the file changes on disk, with conflict handling while editing
• An edit mode for quick raw-text tweaks alongside the reading view
• Customizable fonts, color themes, and syntax-highlight colors
• Print and self-contained HTML export, including offline math