KhiCAS50 is the latest version of the port of Giac/Xcas to the FXCG50, it's a large addin (4.5M) split into two files: https://www-fourier.univ-grenoble-alpes.fr/~parisse/casio/khicas50.g3a and https://www-fourier.univ-grenoble-alpes.fr/~parisse/casio/khicas50.ac2

Compared to the previous KhiCAS port on the Prizm (https://www.cemetech.net/forum/viewtopic.php?t=14888), it provides a more complete port of the CAS with a 3d rendering engine for 3d plots and additional applications like 2d *and* 3d geometry, cf. https://www-fourier.univ-grenoble-alpes.fr/~parisse/casio/geoen.html, a MicroPython port with many modules, exact/symbolic spreadsheet, ...
Improvements also include more RAM (500K) available for computations and the opportunity to run the addin faster (processor overclock). With Khicas50, your FXCG50 becomes features-wise comparable to the best CAS calculators on the market for about half the price!

Documentation and complete install instructions (including emulator install) https://www-fourier.univ-grenoble-alpes.fr/~parisse/casio/khicasioen.html

Special thanks to Lephe, without him this new addin would never have been available.

This seems really cool!
I would try it out but it won't fit on my AU version.

Is the addin open-source?

Yes, cf. the section Developer info in the documentation.

Is there a more lightweight version of KhiCas50? Like dr-carlos, I want to try it out, but it won't fit on the AU version. Thanks!

The light version is the KhiCAS all in one addin
https://www-fourier.univ-grenoble-alpes.fr/~parisse/casio/khicasen.g3a
Obviously some features are missing: 3d, geometry app, symbolic spreadsheet, micropython.

If this was a thing for the CE tho

It's impossible on the CE... The FXCG50 has a far superior hardware than the TI84, and for a lower price. Spread the word!

The CE has a much larger community, and if some people from that community stopped thinking of the cg50 as a 'stupid french calculator', some amazing projects could be created.

The CG50 isn't even the french variant, it's the international one already, so who says that anyway?
(the french variant of that model is the "Graph 90+E")