Hy is a dialect of the Lisp programming language designed to interact with Python by translating s-expressions into Python's abstract syntax tree (AST).

[2][3] Hy was introduced at Python Conference (PyCon) 2013 by Paul Tagliamonte.

[4] Lisp allows operating on code as data (metaprogramming), thus Hy can be used to write domain-specific languages.

[5] Similar to Kawa's and Clojure's mappings onto the Java virtual machine (JVM),[6][7] Hy is meant to operate as a transparent Lisp front-end for Python.

[8] It allows Python libraries, including the standard library, to be imported and accessed alongside Hy code with a compiling[note 1] step where both languages are converted into Python's AST.