Apertus is the open source 8b and 70b LLM from swiss-ai. They've published both the base and the instruct sft models. Very cool that projects like this exist.
I haven't tried it for anything myself yet. The paper provides several benchmarks. The emphasis during training was on multi-language support (over 1800 languages are represented in its pre-training data, which is 40% non-English) and non-copyrighted training data... and the benchmarks seem to suffer for it.
https://apertvs.ai/pages/documentation/
https://arxiv.org/abs/2509.14233