It is pretty easy to use the Kindle App for Windows or Mac to download your ebooks and find them on your harddisk. If the publisher hasn't enabled DRM, you can

It is pretty easy to use the Kindle App for Windows or Mac to download your ebooks and find them on your harddisk. If the publisher hasn't enabled DRM, you can use the files as you like and even convert them in other formats (think: Calibre). In addition, there is no need to buy a Kindle e-reader or Kindle Fire to read Kindle ebooks - odds are you already own a couple of devices with an available Kindle app waiting for you for free. There is even a webbased reader. That said, the Kindle platform might not be the best choice for complex non-fiction titles.