Web app for computing apportionment methods, available at https://pref.tools/apportionment.
To use, just open apportionment.html in a web browser, served from a web server (e.g., python3 -m http.server). The app is written in JavaScript and does not require any server-side processing. The script doing the calculations is in apportionment.js, which is derived from the Python scripts by Martin Lackner: https://github.com/martinlackner/apportionment.