Eclipse Che is an extensible and customizable developer-workspaces platform.
There are three different ways to extend Eclipse Che:
Alternative IDEs allow to provide specialized tooling within Eclipse Che. For example, a Jupyter notebook for a data analyst. Alternate IDEs can be based on Eclipse Theia or any other web IDE. The default IDE in Eclipse Che is Che-Theia.
Che-Theia plug-ins add capabilities to the Che-Theia IDE. They rely on plug-in APIs that are compatible with Visual Studio Code. The plug-ins are isolated from the IDE itself. They can be packaged as files or as containers to provide their own dependencies.
Stacks are pre-configured Che workspaces with a dedicated set of tools, which cover different developer personas. For example, it is possible to pre-configure a workbench for a tester with only the tools needed for their purposes.
Extending Eclipse Che can be done entirely using Eclipse Che. Since version 7, Eclipse Che provides a self-hosting mode.