Instead of implementing separate VMs for each language, GraalVM + Truffle work as an abstract framework for high-performance language implementation. Languages are "dialects" (Truffle AST interpreters) into a shared optimizing compiler backend (Graal).

Most runtimes optimize one language. We optimized across language boundaries.

- Import Python modules from TypeScript - The JIT compiler inlines across language borders - Unified garbage collection across languages - Type information flows between languages