Linux kernel links

I enjoy playing with the Linux kernel code, and over the years I've collected a bunch of links to kernel related information. Below you can find some of those links.
These links have all been of great use to me, hopefully they will be of use to you as well.
If you are not interrested in Linux kernel development, then these links are unlikely to be of relevance to you.

The Linux Kernel Archives

The Linux Kernel Archives aka kernel.org is where new releases of the Linux kernel are published and old versions archived. There is also Changelogs available as well as work-in-progress git trees published by many of the kernel developers.
If you are looking for the latest Linux kernel source code, be it development release, nightly snapshot or stable version, this is the place to go.

The linux-kernel mailing list FAQ

The LKML (Linux Kernel Mailing List) is where most communication related to Linux kernel development takes place. In this FAQ you can find answers to the most common questions about the list; like how to subscribe, how to ask good questions, how to behave on the list and much much more. Be sure to read through it before you subscribe.

LXR / The Linux Cross Referencer

LXR is a great little tool that indexes the Linux kernel and lets you browse the source online. It also lets you search for function names, variables etc and when viewing code all structures, variables, functions etc are links to their definition. A nice way to browse the source for something.
Beyond being an online Linux source browser, LXR is a tool you can download and use to index your own source code repositories - it is not tied to Linux, it can index and cross reference your own pet project as well.

LinuxMM

A wiki dedicated to documenting how the Linux kernel memory management subsystem works. Lots of good MM info can be found here.

Linux Kernel Newbies

This is a website dedicated to people who are just starting out with kernel development. It has lots of basic information about the kernel, lists of tasks that need doing that are suitable for beginners and more. It's a good place to start if you want to join in and help develop the kernel.

Anatomy of the Linux kernel

This is a IBM developerWorks article written by M. Tim Jones that good (but short) overview of the Linux kernel. Worth a read.

KernelTrap

News site dedicated to Linux Kernel development.

LKML.ORG - the Linux Kernel Mailing List Archive

An online archive of the linux-kernel mailing list. If you want to keep up with messages on the list without subscribing, this is a good place to go.
If you want to search for older messages to the list, then the archives at http://www.uwsg.indiana.edu/hypermail/linux/kernel/ or http://marc.info/?l=linux-kernel are probably better places to go.

Linux Test Project

The Linux Test Project is a huge suite of tests that can be used to check for regressions in the kernel, test performance, check standards compliance and much much more.

KLive: Linux Kernel Live Usage Monitor

This project aims to track how much testing different versions of the kernel are getting. It does this by means of a small application that users can install that then reports back to the project what kernel they are running and other related details. On the website you can browse the data collected, such as uptimes for different kernel versions, what hardware the kernels are getting run on and similar.