MacDown

Archimedes is a Markdown and LaTeX editor built from the ground up for the Mac and designed to make mathematical writing fun and easy. At its core, Archimedes is a fully-featured plain text and Markdown editor. It includes a fast syntax highlighter and provides convenient keyboard shortcuts for common actions, such as inserting images and links. With complete support for Markdown, Archimedes makes formatting and structuring documents elegant and easy. In Math Mode, Archimedes lets you write mathematics in a subset of LaTeX, making it an approachable LaTeX editor. Just enter $$ to get started. Over 700 intuitive commands, such as \sqrt{a^2 + b^2}, help you produce stunning mathematical output. Archimedes even autocompletes commands and intelligently matches closing braces, brackets, and parenthesis as you type.

Quiver is a notebook built for programmers. It lets you easily mix text, code, Markdown and LaTeX within one note, edit code with an awesome code editor, live preview Markdown and LaTeX, and find any note instantly via the full-text search. A note in Quiver is comprised of cells, snippets of text, code, Markdown, LaTeX (via MathJax) or diagrams (sequence diagram, flowchart). You can freely mix different cell types within one note. You can set different languages for different code cells, too. The programmer's notebook should make code editing effortless. Quiver packs the awesome ACE code editor in code cells, with syntax highlighting support for more than 120 languages, over 20 themes, automatic indent and outdent, and much more. Quiver lets you write in Markdown with inline formatting and custom CSS options. A live preview window renders Markdown as you type. Quiver uses MathJax to typeset mathematical equations written in LaTeX.