ForeverVM provides a secure platform for running arbitrary, stateful Python code. It utilizes the concepts of machines and instructions, where machines represent stateful Python processes and instructions are Python statements or expressions executed on those machines. The platform manages machine lifecycle, automatically swapping idle machines from memory to disk and back as needed, allowing for long-running repls. It offers both a CLI and an SDK for interacting with machines, enabling developers to build applications that require persistent, isolated Python environments, especially for AI-generated code.