SuanPan, Another structural calculation program, perhaps it is interesting?
https://github.com/TLCFEM/suanPan
Interested.
suanpan -f csmq4.supan -o csmq4.txt
Need a lot of read from https://tlcfem.github.io/suanPan-manual/latest/
Plot01.jpg
Glad it catches some eyeballs. Please feel free to let me know if there are any issues. 
That’s an interesting and quite advanced solver. But it seems that there’s no single list with currently supported FEM features. I’ve found them only here: https://tlcfem.github.io/suanPan-manual/latest/Library/Overview
Can you consider adding such a list to the readme page on GitHub ? Something like this:
FEM Features:
- elements: truss, beam, plate, shell, brick, ...
- materials: elastic, plastic, Drucker-Prager, ...
- constraints: embedded, MPC, rigid wall, ...
- steps: static, dynamic, arc-length, ...
...
It could be helpful for users looking for an open-source solver capable of doing what they need.