Here’s a quick attempt to group live coding systems by popularity / usage in the live coding / algorave community (apologies if I offend anyone, this is super informal, quick & coarse guesstimate):
First Tier
TidalCycles, Orca, Sonic Pi, Hydra, SuperCollider
Second Tier
Gibber/Gibberwocky, FoxDot, Extempore, Estuary, KodeLife, ChucK, Cyril, Fluxus, Veda, ixi lang
Third Tier
so many great systems! clive, live csound, praxis live, la habra, the list goes on forever.
A lot of it depends on what you’re trying to do. I have my biases, but it’s objectively true that gibberwocky enables live coding practices in Max that would be impossible to achieve in any other existing systems (live coding gen~ expressions, for example). TidalCycles is incredibly powerful/fun, has an amazing community and is actively maintained… by more than one person (the downfall of many live coding systems). Sonic Pi has the widest adoption in education, but is also used by many experienced live coding performers. Hydra is soooooo fun sooooo fast. FoxDot has great collaborative performance affordances and lets you use Python to control SuperCollider. Orca gives a completely different live coding experience that has attracted lots of people in the llllllll community.