The main page for this idea is Summer Coding 2010 ideas - Ink level reporting for printer drivers.
Summary of idea: Several printer drivers are capable of reporting the amount of remaining ink or toner in the printer they are driving, but they all do it in different ways. Usually there is a command line program that the user has to know about and run (and interpret the output). For gutenprint there is escputil. For HPLIP there is hp-levels. And so on.
CUPS provides a unified framework for all drivers to report marker levels in the same way, viewed and queried from a single user interface. The same interface can be used for other "special" functions such as cleaning/aligning the print heads, printing a self-test page, etc. We just need the printer drivers to conform to this way of doing things.
Changing both gutenprint and hplip would be sufficient to cover a large number of printer models.
Contacts: Tim Waugh
Mentor(s): Tim Waugh