I posted an earlier version here before as a learning project. Since then I have been moving it toward a more practical direction: v0.2.0 adds a C embedding API and builds the runtime as libpico. A host program can now create a VM, evaluate PiCo code, register native C functions, call PiCo functions from C, capture output/errors, and prevent scripts from terminating the host process.
It is a small toy language. The current public value API is intentionally limited to null, bool, and number.