Active Java Kernels

• Rapaio - release in 2023 Rapaio Jupyter kernel works with Java 21.
• Kotlin - The kernel is a powerful engine designed to enhance your Kotlin REPL experience. It offers support for executing code cells, providing basic code completion, and analyzing errors
• Ganymede - a Jupyter Notebook Java kernel based on the Java Shell tool, JShell.
• JJava - a kernel for Java. Started as a fork of iJava, but is fully supported and constantly adding new features.
• Almond - A kernel for Scala.
• Toree - A kernel for Spark written in Scala.

Inactive Java Kernels

• IJava - the "original" Java kernel. Not actively maintained.
• SciJava Kernel - Defunct kernel based on BeakerX.
• java9_kernel - defunct Java 9 based kernel. On this list as has interesting approach on wrapping/calling from python.
• BeakerX - BeakerX is a collection of polyglot JVM kernels and interactive widgets for plotting, tables, autotranslation, and other extensions to Jupyter Notebook and Jupyter Lab version 1.2.x and 2.x. Seems somewhat defunct.
• JSR223 Kernel - A JSR223 compliant Jupyter kernel implementation in Java.

Java Related Kernels

• Polyglot Notebook VSCode - Supports various lanuages from .net family, but has a Java feature request dotnet/interactive#3084

Online Jupyter Notebook Java capable environments

• mybinder
• Google Colab
• Red Hat OpenShift Sandbox with Red Hat DataScience
• GitPod
• GitHub CodeSpaces
• OpenShift Workspaces

Jupyter Auxiliary Libraries

• jupyter/jvm-repr - API for converting JVM objects to representations by MIME type, for the Jupyter ecosystem.
• jupyter/jvm-magics - A plugin system for magic function implementations across JVM kernels.
• spencerpar/jupyter-jvm-basekernel - Base kernel to use for base implementation of a Jupyter Kernel

Not Jupyter but similar for Java

• jnotebook - a modern notebook system for Java. jnotebook interprets Java JShell files and render them as notebooks.
• Apache Zeppelin - Web-based notebook that enables data-driven, interactive data analytics and collaborative documents with SQL, Scala, Python, R, Java and more.