JupyterLab is the next-generation user interface for Project Jupyter
offering all the familiar building blocks of the classic
Jupyter Notebook (notebook, terminal, text editor, file browser,
rich outputs, etc.) in a flexible and powerful user interface.
JupyterLab will eventually replace the classic Jupyter Notebook.

Jupyter kernels are needed for JupyterLab to be fully functional. The
following kernels are currently available as SlackBuilds:
* jupyter-ipykernel

jupyterlab 3.5.3 is the last possible version for Slackware 15.0.
Newer versions would require a newer jupyterlab_server.