ETHZ / EPFL have just published their fully open source #Apertus LLM: https://ethz.ch/en/news-and-events/eth-news/news/2025/09/press-release-apertus-a-fully-open-transparent-multilingual-language-model.html
Unfortunately, the quality isn't quite there yet... it fails the usual trick questions ("how many L in pizzeria"), regurgitates some inadvertent training material (e.g. when asking "Wie würdest du die Schweiz beschreiben?", "how to describe Switzerland?") and makes Grammar mistakes in German.