Sympy.jl tries to provide a Julia-like interface to python SymPy. They are intended to be used, for the most part, programatically. Symata tries to follow Mathematica semantics. In particular it is a separate language written in the host language Julia. However, I put a fair amount of effort into allowing a user to break this separation, and to interact with Julia. In particular, one can use Symata from Julia programs. In fact, that seems to be the way people prefer to use it.