There are a large number of people who do kernel-level integration work-- configuring things, downloading drivers, setting things up, and otherwise dealing with the hardware.  This kind of work isn&#x27;t the most glamorous, but it definitely counts as &quot;actual contribution&quot; to the community.  Integrators find bugs, make suggestions on mailing lists, and help develop products that make investing in Linux worthwhile for everyone involved.  Most integrators that I&#x27;ve known like to submit patches every now and then, just for fun.<p>I would guess that there are more people whose primary job is integration than people whose primary job is kernel development.  I don&#x27;t really have any concrete numbers, though.  On the driver development side, companies are starting to get smarter about getting their code upstream first-- look at NVidia and Intel&#x27;s recent efforts in that area, for example.