Last week, Amazon announced that they will be releasing an SDK for creating Kindle Apps. I know that three days before the big Apple Tablet/Slate/Canvas announcement, I’m supposed to be getting ready to tabletize my app, but the idea of developing for the Kindle is looking kind of interesting.

Given that the beta isn’t out yet — there isn’t a lot of information about the KDK yet. However, there have been some successful hacks of the Kindle and Amazon was forced by the GPL to publish their modifications, so we do know some things:

1. The Kindle runs Linux
2. Kindle GUI’s are written in Java
3. There will be three models of apps, free, one-time purchase, and subscription. The first two will have a monthly bandwidth cap of 100KB/user.
4. Advertising is listed as something you can’t do — perhaps they mean an app that only advertises, but even so, why not? Mobile advertising is large part of the app ecosystem, so I assume in-app advertising will be allowed.
5. A generic reader is not allowed — again, does this mean a PDF reader wouldn’t be allowed? I can see Amazon not wanting the 3G being used to buy from other stores, but why not let me read content I get from other means (or from subscription apps).

The brevity of the developer guidelines is welcome, but I hope they elaborate on them in the near future.