mathics seems really cool. I was thinking of biting the bullet and buying a copy of mathematica since I'm teaching myself higher level math and want a a language that does symbolic computation. Needing to pull a docker file to run seems like a bit of a pain though...
You could also try Wolfram Cloud. Only significant issues a free account has is the inability to upload (so cannot use found notebooks unless you retype everything yourself) and files expiring (becoming unavailable unless you pay) after 60 days. But give Mathics a chance first.
