My colleague John Timmer reported yesterday on Amazon's new Kindle e-book reader. Kindle's software platform unsurprisingly runs on the Linux operating system and uses numerous open source software components including Alsa, zlib, busybox, and Freetype.
In compliance with the licenses governing these various components, Amazon has made the source code available from their web site, which makes it possible to see what Amazon has changed. In a blog entry yesterday, Linux kernel hacker Robert Love provided a link to a diff he generated which shows how Kindle's Linux kernel deviates from the standard Linux 2.6.10 kernel.
http://arstechnica.com/journals/linux.ars/2007/11/20/linux-on-amazons-kindle-e-book-reader