> The rule as written means contractors who write Windows drivers could deduct their expenses (as they would have no residual rights to a closed-source work product), but contractors who write Linux drivers may not (as they would have some rights to open-source Linux drivers).
Is it just me or are you conflating two orthogonal things?
An open-source Windows driver would have the same issue, no? And a closed-source proprietary Linux driver privately written for some company wouldn't have this issue either, right?