Link: Modifying The Linux Kernel.

This is an article that provides instructions on ways to modify the linux kernel. It's interesting to understand how one can customize one's own operating system.

As the author described at the end of this article:

Can you think of some new interesting features you can add? Maybe it will be your next coding project.

1. LBYPatrick: Google has done such thing to utilize their now-merged-by-linux TCP congestion algorithm called BBR. Read this article for more information.