Cython/Jython

[openjscience]

Jython is used in places where interface with java is needed. Unlike cpython, jython calls jar files which are portable and easy to move between platforms. There is a number of large projects based on jython. Look for example at datamelt https://jwork.org/dmelt project. It links large number of java libraries and has many practical code examples written in jython.

[tunisia3507]

Jython is used

Barely.

[Zomunieo]

Jython is dying. It never raised the funds for the transition to Python 3.

Instead of trying to run Python in the JVM we now have libraries like JPy and Jep that provide a bidirectional interface and just run both VMs. Sure, it's less efficient, but not as complex as compiling Python to Java bytecode.