I’m a multitasker. I can switch the context quickly in my head, but switching the context on a computer is a very sluggish process. Think about starting Eclipse… And a couple of other frameworks based on it. And Firefox with multiple tabs. And an email client with a few open relevant emails. And a few other applications you have to log into… And so on. Right, it will take 10 minutes easily for a 10-15 minutes task. It’s a time killer.
It looks like very little is needed – just ability to serialize and deserialize an application/process in an operating system with all open windows and unsaved data to a file. Then if you need to switch from one task to another, you could save your context, close applications (should be done automatically) and start the other task by opening a context file saved previously.
There are some “implementations” available. Firefox can save a session and then restore it (although you are allowed to save only one session per profile which is a drawback). Windows and MacOS has an ability to save a user session and power off the computer, but again, only one session and it just shuts off the computer. This is done at the ACPI driver level. There is a workaround though, you get multiple computers and switch between them, but this is a very expensive option. Another way is to have multiple virtual machines, but this sounds like overkill. Eclipse Mylyn is the closest, but that just of Eclipse only.
Windows is more that 15 years old, but still does not have this feature. Am I asking to much?