That is a kernel panic, which is no fun to deal with. This is a nice little overview of panics – https://www.thexlab.com/faqs/kernelpanics.html
But the easiest things to check/do are
-Unmount all your external drives
-Open the mac and make sure all the cards are seated correctly
-Keep in mind one of those cards might be causing the panic, so if you have extra cards like firewire expansion cards, SATA, an AJA, etc, you might eventually have to take them out one by one and see what’s causing the error.
-Check your RAM- is it seated properly? Installed properly? Bad installation or bad RAM can do bad things to macs.
Sometimes an OS reinstall is required. Fun times!
For grins I would repair permissions and flash the PRAM.