Lean is a general purpose programming language created by Apple Inc. It is based on the Swift programming language and uses LLVM as its compiler infrastructure. Lean was designed to be a safe, fast and expressive language with an easy-to-use syntax.
Lean's primary focus is on application development, but it is also suitable for systems programming. It has a rich set of libraries and tools that make it easy to develop sophisticated applications.
Lean is open source and contributions are welcomed from the community.