Boa is an experimental JavaScript engine written in Rust that supports over 90% of the latest ECMAScript specification. It includes a lexer, parser, and interpreter, and offers various crates for different functionalities. Users can run JavaScript code via a CLI or in a WebAssembly environment.

Monty is an experimental Python interpreter built in Rust, designed to run Python code generated by AI agents. It offers fast startup times and strict control over resource usage while limiting access to the host environment. Although it has significant limitations, such as no support for the standard library or third-party libraries, it aims to simplify executing code from LLMs.