MRML is a Rust-based implementation of the MJML (Mailjet Markup Language) parser and renderer. It provides a core library for converting MJML templates to responsive HTML email, along with CLI, WebAssembly, and Python bindings. The architecture is modular, with each MJML component following a consistent pattern for parsing, rendering, and serialization. The system supports template inclusion via pluggable loaders (memory, local, HTTP) and includes an HTTP server example for rendering MJML via a POST endpoint.