The latest incarnation of the Linux Kernel was released this week, and for the first time, it includes code for running Linux on Google Chromebooks. Chromebooks come loaded with Chrome OS — a web-happy, Linux-based operating system designed by Google — but the new kernel code will make it easier to run other versions of the popular open source operating system on these machines.

A kernel is the most fundamental component of an operating system. It handles critical tasks like communicating with hardware and managing resources. But there’s much more to a Linux distribution — such as Ubuntu or Red Hat Enterprise Linux — than the kernel. There are also desktop environments, such as GNOME and KDE, and application frameworks like GTK and QT.

Android, like Chrome OS, uses the Linux kernel. Apple’s Macintosh OSX operating system uses code from another UNIX-like open source kernel operating system called BSD. But Android and OS X have their own environments and frameworks, which is why applications written for those OSes aren’t generally compatible with Ubuntu or FreeBSD. It also means that if you want to run more sophisticated Linux applications on a Chromebook, you’ll need to install a full Linux distribution instead of Chrome OS.

Hobbyists have already been installing Ubuntu on Chromebooks using an independent version of the distribution called ChrUbuntu. Now that drivers required to use a Chromebook are being bundled into the kernel, other Linux distributions will have some of what they need to run on Chromebooks baked right in. But there are two caveats:

1) Most Chromebooks have a bootloader that restricts the installation of other OSes. If you’re not using Google’s own Chromebook Pixel you’ll still need ChrUbuntu for its alternate bootloader.

2) At this time support is limited to x86 based Chromebooks — users with ARM-based Chromebooks will still have to wait for support.

Still, these improvements will bring Chromebook users more choice, and make it easier for those who want to try Linux to do so on low cost Chromebooks.

Other changes in Linux 3.9 include various performance improvements, solid state drive caching, and support for running Red Hat’s virtualization system — KVM — on ARM processors.

Other recent updates to the kernel have been more noteworthy for what they removed than for what they added. For example version 3.6 dropped a tasteless joke inserted by Microsoft. And version 3.8 dropped support for 386 DX33 machines — including very system that Linus Torvalds used to program the very first version of Linux.