At work I discovered that one of our network connected temperature monitoring devices is functional but old.
How old? The web browser NPAPI Java plugin is required to access the device settings.
Without the Java plugin the device is not configurable. I created a Slackware 11 virtual machine (VM). That version of Slackware came with Java and the plugin. This was the last release of Slackware that came with the Java and plugin packages. Then the Oracle folks got anal about licensing. Remember those days?
With the VM I connected just fine.
Only to discover the firmware can’t be updated that way. Proprietary software from the vendor is needed to update the firmware.
The proprietary software is Windows only.
The monitoring device will live on as-is and die as-is.