These are the individual projects that make up the Yocto Project. Each of these holds a key role in developing embedded Linux, and the Yocto Project works to make all of them interoperable and useful.
NOTE: Hob is now deprecated and will no longer be available beginning with the 2.1 release of the Yocto Project. You can use Toaster instead. Hob will still be available inside the Build Appliance, but might not work as expected, since it is no longer maintained.
The Build Appliance is a virtual machine image which enables you to build and boot a custom embedded Linux image with the Yocto Project using a non-Linux development system. We don't recommend that you use the Build Appliance as a day-to-day production development environment. You should limit the Build Appliance to testing out and experiencing the Yocto Project. The Build Appliance leverages other projects in the Yocto Project, particularly Hob, which boots inside the virtual machine.