I've used Debian with Mate desktop on a 2009 MBP for a several years. Ran fine with 4GB RAM and retro-fitted SSD. Just installed Debian from a USB flash stick.

I've used Debian with Mate desktop on a 2009 MBP for a several years. Ran fine with 4GB RAM and retro-fitted SSD. Just installed Debian from a USB flash stick. The same one that I have used on non Apple x86-64 systems.