Today in my History of Computing class, the lecture was about the time in IBM's life when the company decided to unbundle software from hardware. The decision to unbundle was made in the mid-1960s, and a task force was put together in order to figure out exactly how to do it.

They weren't concerned about how to price the software. Mostly, they wanted to know how they could `protect' their software. They thought about patents, but at the time, they didn't even know if software could be patented. Also, they didn't feel it was a good idea to flood the Patent Office with SW patents.

Next, they thought about protecting their code by making it a trade secret. Unfortunately, that doesn't work very well either, since once a trade secret is out in the open, it ceases to be a trade secret and no longer has any legal protection. It would be very hard to keep it secret, because of the large numbers of developers that would have to interact with it regularly.

Lastly, they considered copyrighting the stuff, but the folks at IBM thought that copyright protection was very weak and didn't provide for much. I'm not sure if my prof said exactly what they decided, but I suppose that all of this is why we have all sorts of crazy software licenses today.