[2bitencryption]

If you're even slightly interested in getting into jailbreaking/hacking of devices, the Kindle is a great place to start.

There's a lot of low-hanging fruit there. Particularly because the device has a USB port and, by design, exposes a user partition that you can read/write to (so you can upload files and documents and ebooks to the device).

There's definitely been an effort by Amazon to lock them down, but just taking your reverse-engineering tool of choice and decompiling their firmware binary will give you tons of readable code to dig through. They use a mix of java, native c, and javascript.

Fun fact, at startup the Kindle looks for certain files in the user partition, with certain naming patterns. You can, for example, disable the screensaver by dropping a file with a special name there. They patched this once, but after doing a grep for the user-partition mount location (to see all the places in their code where they read from user partition files) I was pretty quickly able to find another way to do this. It's fun stuff.

[miohtama]

Are new Kindles still hackable or are they fully closed like consoles?

[theoreticalmal]

I looked into it precisely once, and found a bunch of results that the newer firmware versions didn’t have jailbreaks available, and that downgrading wasn’t feasible. I’m hoping to be proven wrong though…