You can now directly upload arch-style diagrams to Wikimedia Commons under your own username with this new interface. Please submit bug reports and feature requests at the project's issue tracker
This is a tool to generate arch-shaped parliament diagrams.
To use this tool, fill in the name and support of each party in the
legislature, clicking "Add a party" whenever you need to add a new party. Then
click "Make my diagram", and a link will appear to your SVG diagram. You
can then freely download and use the diagram, but to use the diagram in
Wikipedia, you should upload it to Wikimedia Commons. You can now do this
directly, by clicking on the green button to create an upload link. Click on
the link and follow the instructions: it will upload the file under your
username, including the list of parties in the file description. This tool
will automatically add your file to the
election apportionment diagrams
category, but you should categorise it in more detail after uploading.