Glow is a terminal-based markdown reader written in Go. It provides both a CLI mode for rendering markdown files directly to the terminal and a TUI mode for browsing and reading local markdown files with a pager interface. The application supports reading from files, stdin, HTTP URLs, and GitHub/GitLab repositories via their APIs. It features syntax highlighting via Glamour, word wrapping, custom styles, and a configuration file. The architecture is modular: the main entry point parses commands and arguments, delegates to either the CLI renderer or the TUI program, which is built on the Bubble Tea framework. The UI is split into a stash view (file listing) and a pager view (document rendering), with models and views separated. A notable feature is support for Kitty terminal's text sizing protocol (OSC 66) to scale heading sizes, implemented in a self-contained utility module. The codebase demonstrates strong Go practices, clean abstractions, and thorough testing.