phosphor
Domain: JupyterLab GUI
🎯 Motivation
The predecessor library to Lumino. JupyterLab 1.x used PhosphorJS; it was renamed to Lumino in JupyterLab 2+.
📋 Concrete Example
Old extensions imported from @phosphor/widgets; the equivalent today is @lumino/widgets.
🔗 Analogy
Phosphor is the old brand name; Lumino is the relabelled same product on the shelf.