> But AIX is now very definitely a profit centre. When it can no longer compete in customers' minds, and starts losing money, it will be gone.
It's hella expensive to migrate away from it. Just like any enterprise platform that a large-ish corp depends on for core functionality. The time and money it will take for most companies to move away from AIX far outstrips the cost of keeping it.
(Not to also mention the risk to your career if you decide to take something that is working and replace it with something that is cheaper... only to find the new solution doesn't work.)
IBM knows this and sets up licensing accordingly and will continue to make a killing for a very long time.
If it wasn't for this fact 'big iron unix' would of been dead years ago, I expect.