To write safe smart contracts you need a safe language. Pact is immutable, deterministic, and Turing-incomplete, fighting bugs and exploits while offering the full power of a high-level language. Atomic transactions keep your data sane.
Based on LISP, Pact strikes a balance between low-level directly executable expressions and high-level declarative code. It parses fast and executes faster, and is stored unmodified on the ledger: you always know what code you're running.