While some other languages and platforms may work, we only support JavaScript and Node.js.
All Node packages should work fine (you can include them in your package.json file). If they are not working, it may mean that they are not compatible with the version of Node your project is running.
If you need help using other languages and platforms on Glitch, you can ask for advice in the Coding section of our Community Forum. There, you will find fellow app makers who may have some useful suggestions.