I'm not sure if this offers any additional features, but it seems like a similar tool to https://www.geogebra.org/calculator which I believe is also open source.

The key word in the title is symbolic. In GeoGebra the CAS is not coupled to the drawing, and most of the computation on the drawings are numerical. In the link, everything you draw is symbolic and you get an algebraic expression in terms of the primitives you specify.

That's true, but you /can/ do exact geometric constructions that just use the CAS engine in GeoGebra eg https://www.geogebra.org/m/ZdhcBBpj

That's excellent, that is not nearly as difficult of syntax as I was expecting.

Many years ago I worked briefly for this company. It’s nice to see them hit the big time.

This really needs a "new here? here's how to use this tool!" tutorial. It's no doubt super cool, but how do you actually use it, without first clicking random things until "something does a thing"?

The examples under the help menu, (?) icon, are pretty good: https://geometryexpressions.com/gxweb/help/ ... at least the ones I looked at in the Some Geometry Theorems category now.

Very cool. Maybe I'll finally learn geometry proofs now!