Apertus: a fully open, transparent, multilingual language model

First "modern and powerful" open source LLM?

Key features

• Fully open model: open weights + open data + full training details including all data and training recipes
• Massively Multilingual: 1811 natively supported languages
• Compliant Apertus is trained while respecting opt-out consent of data owners (even retrospectivey), and avoiding memorization of training data