Which one of both companies contribute the most to Linux open source projects, excluding their own driver support?

Browsing the net I've noticed that Intel is a big time supporter of Linux and open source and I've found nothing special about AMD except for their the development of their own drivers for Linux.

I'm planning to buy a new PC and was initially going for AMD + Nvidia (I've always been an AMD supported in the past as a Windows user) but since AMD doesn't seem to be very active (correct me if I'm wrong) in Linux desktop development, I may consider paying a bit more for Intel + Nvidia hardware.

I noticed that only Intel of the two actively develops the X project which is like the second important part of the Linux desktop so I may go choose for Intel instead depending on the feedback.

Thanks in advance