Read around a bit and found a community maintained fork which seems to be a bit more updated (https://github.com/arclanguage/anarki), is that what people tend to use?
Yes, it's the fork that's been maintained by the people here at Arc Forum. :) I recommend it.
Whether you want the community additions or not, you might also be interested in the "official" and "stable" branches of that repo. The "official" branch tracks the official .tar releases that you'd find on the front page here, and the "stable" branch tracks the official releases plus a few small bug fixes and quality-of-life improvements.
