karlatk

Karlatk is a high-level, statically typed programming language designed for safe, verifiable smart-contract development and general-purpose systems programming. It was created by a collaborative open-source project in the early 2020s, emphasizing formal verification, deterministic execution, and readability. The language supports strong safety through a borrow-checker-like system, a rich type system, and built-in specification constructs for proofs.

The name karlatk is a coined term chosen by its designers; it does not represent a widely used acronym. Key features include algebraic data types, a formal specifications language embedded in the syntax, contract modules, and a verifier that generates proof obligations. It compiles to WebAssembly and native binaries, enabling deployment on blockchain nodes or conventional servers. The standard library provides concurrency primitives, asynchronous I/O, and a lightweight cryptography module.

Karlatk originated from an open workshop in 2021 and was released as an early-access project in 2022. It has attracted a small academic and developer community, with several toy blockchain projects using it for formal verification experiments and safe contract patterns.

Impact and reception: While not broadly adopted, karlatk has influenced discussions about verifiable smart contracts and informed the design of verification-oriented features in other languages. The community continues exploring integration with existing platforms and educational curricula.

See also: Rust, Move (blockchain language), Solidity.