The Python implementation designed to run on the Java platform is Jython.
Jython is an implementation of Python that runs on the Java Virtual Machine, allowing Python code to interact directly with Java classes and libraries. It can compile Python source into Java bytecode, which makes it useful in environments where Java integration, JVM tooling, or Java-based application servers are important.
The project was originally called JPython and was known by that name until 1999. Early development began in the late 1990s, and the project later moved to SourceForge. Jython includes much of Python’s standard library, although modules implemented specifically in C may not work without adaptation. It has been used in tools and systems including WebSphere administration, Ghidra plugins, and industrial automation platforms.
Jython is often mixed up with IronPython, but the platforms differ: Jython targets Java and the JVM, whereas IronPython targets Microsoft’s .NET ecosystem. CPython is Python’s standard implementation in C, and PyPy is a separate implementation focused heavily on performance and just-in-time compilation.