There is the dali-interface Python library which seems to support a few PC DALI interfaces based on USB-HID and serial. I don’t know how well the translation between USB-HID/serial and DALI is standardized, so I can’t tell you how compatible this library is with DALI interfaces that are not explicitly listed in the README.
Software using this library includes dali_mon for monitoring the DALI bus and dali_cli for sending commands.










I wouldn’t say the extension was the beginning of the downfall; that kinda implies it caused the downfall.
I would agree that it was the canary in the coal mine – management types were ramping up their “just jam X into it” attitude, techies were starting to really feel it, and this was an initial, small protest. Unfortunately, despite the techies’ well-communicated newfound capability to run applications in my butt, the management types kept focusing more and more on their hype-oriented strategy – but that would certainly have happened without the extension too.