1. kernel.org — The Official Home of the Linux Kernel

Before you write a single line of kernel code, you need the source. There is exactly one official place to get it: kernel.org. This site is maintained by the Linux Kernel Organization and hosts every version of the kernel ever released — stable releases, long-term support releases, and the bleeding-edge development tree.

When you visit kernel.org, you see a table with many rows of kernel versions. It can look confusing at first. Let’s understand what each row category means before downloading anything.

2. Understanding Kernel Version Numbers

Linux version numbers follow the pattern MAJOR.MINOR.PATCH. For example, in the version number 6.12.94:

There is no odd/even numbering trick anymore — that scheme was dropped after version 2.6. Every new release simply increments the minor number. Bug-fix updates like going from 6.12.90 to 6.12.94 never add new features — they only fix things that were already broken.

3. Downloading the Linux Kernel Source

The kernel source is released as a compressed tarball in .tar.xz format. Think of it as a very large ZIP file containing millions of C source files. You have two practical ways to download it.

Method 1 — Download via Browser (Simplest)

Go to kernel.org, find the kernel version you want in the table, and click the [tarball] link next to it. Your browser saves the file, usually to your ~/Downloads folder. This is the easiest method if you just want to get started quickly.

Method 2 — Download via Terminal using wget

This is the method every Linux kernel developer should be comfortable with. The terminal lets you script downloads, run them on headless servers, and pick the exact destination path. Here is how to download the LTS kernel 6.12, which is a solid choice for learning in 2026:

# Download Linux 6.12 LTS kernel source
# Update the version number when a newer LTS is available
wget --https-only \
     -O ~/Downloads/linux-6.12.tar.xz \
     https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.xz

Method 3 — Download via Terminal using curl

If wget is not installed (some minimal systems skip it), use curl. It is available on almost every Linux and macOS system by default:

# Download using curl — the -L flag follows any HTTP redirects
curl -L --proto '=https' --tlsv1.2 \
     -o ~/Downloads/linux-6.12.tar.xz \
     https://cdn.kernel.org/pub/linux/kernel/v6.x/linux-6.12.tar.xz

4. Understanding the kernel.org URL Structure

One thing that confuses beginners is figuring out the correct download URL for a specific kernel version. The pattern is straightforward once you see it:

5. What Is Inside the Kernel Source Tree?

After you extract the tarball, you get a folder containing millions of C source files organized into subdirectories. You do not need to understand all of them right now, but knowing the top-level layout helps a lot:

As a kernel module developer — which is where this free Linux kernel programming course is heading — you will mainly work with include/ headers, look at existing code in drivers/ for reference, and check Documentation/ whenever you need the official spec for a kernel API.

6. Stable vs LTS — Why This Matters for Embedded and Device Driver Developers

This distinction is critical if you are planning to write Linux device drivers or do embedded Linux work. Products in the field often run for years — choosing the wrong kernel base can create serious maintenance problems down the road.

Android, for example, is always built on an LTS kernel base. The Android kernel team takes an LTS snapshot and applies their device-specific patches on top. If you are developing a product that will ship to customers, an LTS kernel underneath is not optional — it is a requirement.