Switzerland has announced the launch of Apertus, a new open-source large language model (LLM). Developed as a collaborative effort by ETH Zurich, the Swiss Federal Institute of Technology Lausanne (EPFL), and the Swiss National Supercomputing Centre (CSCS), Apertus is positioned as a transparent and multilingual alternative to proprietary AI systems from major tech companies. The model is available in two sizes, 8 billion and 70 billion parameters, and its name, derived from the Latin word for "open," reflects its open-source architecture, training data, and model weights. The launch of Apertus is a significant step in the European AI landscape, aiming to foster innovation and establish a sovereign AI ecosystem.