I’ve found a raport about who are making changes in the linux kernel, and develop it.

1. Red Hat - 11,2% of the changes
2. Novell - 8,9% of the changes
3. IBM - 8,3% of the changes
4. Intel - 4,1% of the changes
5. Oracle - 1,3% of the changes
6. MontaVista - 1,2% of the changes
7. Cisco - 0,5% of the changes

13,9 of the changes is made of other non-business people. In fact Linus Torvalds only does 0,6% changes himself.

(Source: internetnews.com)