Overview page: https://www.gog.com/en/anniversary
Direct sign up for Galaxy Linux beta: https://www.smartsurvey.co.uk/t/YEF5EV/
OK then I've been mistaken for 20 years. 🙁
But the context that he was running Mac and he criticized the Linux desktop for not being suitable for a daily driver, lead me to this obvious conclusion.
For some reason I have never seen an article before that he uses Mac but with Linux on it??