You have to have the source of what you are trying to learn. If it's a web framework - sure, you can download the source and work on a Windows machine. But you

You have to have the source of what you are trying to learn. If it's a web framework - sure, you can download the source and work on a Windows machine. But you need to realize you are learning about a different system, and one you have the source to. If you want to figure out how operating systems work - you need to see how one works. Learning how to use a system or code in a framework is possible with closed-source. You can even get some work done. But it can't be called hacking, because the aim of a hacker is to understand. Say what you will about esr, but the body cast thing is more true than not.