go-grip
A lightweight, self-contained Go tool that renders Markdown files locally in a browser with GitHub's own styling, without calling GitHub's API.
go-grip renders Markdown files locally with the look of GitHub, opening the rendered page in your browser, and is a Go reimplementation of the original Python-based grip tool. Where the original grip renders through GitHub's web API, go-grip is fully self-contained, which the project says makes it faster, more secure, and better suited to offline use or privacy-conscious users.
It supports syntax-highlighted code blocks, light and dark themes, GitHub-style checklists and emoji, Mermaid diagrams, inline and block math expressions, hashtag-style linking within the page for tables of contents, and GitHub-style callout blockquotes such as note, tip, important, warning, and caution; its rendered table of contents toggle state is preserved in the browser's session storage. It installs with a Go install command, can also be installed via Nix flakes, and is run by pointing it at a Markdown file, opening a browser automatically on a configurable port, or run with no file argument to browse a file tree of everything in the current directory.