The technical report for Apertus 1.5, Apertus 1.5: From Open Text Models to Open Multimodal Reasoners, is now on arXiv! It is the work of the whole Apertus team, and I am proud to have been the coordinator of writing this report.
Read the report on arXiv or Hugging Face Papers, and try the models from the Apertus 1.5 collection.