> If you are a salaried worker at IBM and choose to work on an IBM driver in the IBM kernel driver directory in your spare time isn't that fair?

In that case, everyone would agree that the work was done in their capacity as an employee. The employee isn't going to dispute that, or they'd essentially be admitting to unauthorized use of IBM systems.

What IBM systems?

Perhaps I misinterpreted in the IBM kernel driver directory. I'm imagining a developer remotely accessing their IBM workstation.

The developer could contribute to a Free and Open Source IBM driver on their own time, and reasonably insist that IBM do not get to claim ownership, the same way anyone else can.

Whether that's a sensible choice of personal programming project, is another matter. It's unhelpful to muddy the waters.

No? If it's done in your spare time, it isn't work. Even if it happens to be something you legitimately could have done during work hours.

This is tricky. There is one sense of "spare time" which concerns output - you aren't always expected to be working. But salaried knowledge workers are commonly considered to have no "spare time" in an intellectual sense, especially when it comes to overlap with the company's core competencies.

This is obviously controversial for individual contributors, but it's well established in IP precedent. It's why you can't work at Google and develop a competing product in your off hours, even if it's "on your own time" and on your own equipment.