mshell — Inter-Language Execution Reference Guide.

mshell — Inter-Language Markdown Execution Environment Reference Guide:
mshell reimagines the Markdown document as an active execution environment rather than static text. A single .md file can contain code blocks in seven languages — Bash, Python, C, C++, Rust, Go, and Lua — that run sequentially and exchange data through session variables. The output of a C block becomes the input of a Python block, which feeds an LLM directive, which passes its response to a Rust analyzer. All in one document, no glue code, no temp files managed by hand.
The core idea: treat a document as a pipeline. Variables written with >varname are captured to session context and read by any subsequent block via MSH_VAR_varname. The mechanism is language-agnostic — every language reads a file path from an environment variable, which is the same simple contract for all seven.
Different algorithms and tasks have their natural homes in different languages — C for raw performance, Python for data and visualization, Rust for safety-critical logic, Go for concurrency, Lua for lightweight scripting. mshell lets each language do what it does best, passing results seamlessly to the next stage rather than forcing everything into a single environment.
LLM integration is first-class. Inline directives , , call configured models from Ollama, OpenAI, or Claude without leaving the document. Exec mode goes further — the model generates code and mshell executes it immediately, enabling live visualizations, OpenGL windows, and browser charts produced entirely from a natural language prompt.
The notebook application that ships with mshell adds a GTK-based editor with direct PDF export — making the same .md file serve as both a runnable program and a formatted technical document. No separate toolchain, no pandoc pipeline required.
Tested and working on Ubuntu, Debian, Raspberry Pi ARM64, other Linux OSes, macOS Sequoia (and some previous).
What makes it unusual is the combination: polyglot execution, LLM as a first-class pipeline stage, and documentation generation — all from a single file format that is itself human-readable. If you have any questions based on the Reference Guide you can ask directly here on LinkedIn or send an e-mail to me.