Non-free software is usually unsupported (Multiverse), but some exceptions (Restricted) are given for very important non-free software. Supported non-free software include device drivers that are needed to run Ubuntu on current hardware. The level of support in the Restricted category is less than that of Main, since the developers may not be able to get to the source code. It is wanted that Main and Restricted should contain all the software needed for a general-use Linux system.