Huh. That took me down a rabbit hole. I wasn't aware this was released as open-source. That solves a few unrelated problems for me. Expanding on the above post

Huh. That took me down a rabbit hole. I wasn't aware this was released as open-source. That solves a few unrelated problems for me. Expanding on the above post: Erable was replaced with Xcas / giac, which is the more advanced CAS used on the HP Prime. Almost all of this is open-source (with the exception of small bits of Erable developed by HP, not needed for Xcas /giac), under a mixture of LGPL and GPL3 licenses (mostly the latter). This gives a surprisingly advanced and complete symbolic algebra system for use in your own programs. Although developed in C/C++, it has interfaces to many languages, including oddly enough, JavaScript. In that case, the C/C++ is compiled to WebAssembly with enscripten. But of course, more common ones like Python or LaTeX exist too. It is used in many systems, including Geogebra. It is developed in France, and feels, for a lack of a better word, French. I have the odd experience of having seen SWE culture in several countries, and this is firmly in the French camp. I suspect if it were more American, it would be better-known given the level of completeness and quality.