Date
and time: Friday November 21, 2025 13:15-14:15
Speaker: Martin
Jaggi (EPFL)
Title: Apertus:
Democratizing Open and Compliant LLMs for Global Language
Environments
Venue:
-
Physically at EPFL, BC Building, room BC 420
and
Abstract:
We present Apertus, a fully open suite of large language
models (LLMs) designed to address two systemic shortcomings
in today's open model ecosystem: data compliance and
multilingual representation. Unlike many prior models that
release weights without reproducible data pipelines or
regard for content-owner rights, Apertus models are
pretrained exclusively on openly available data,
retroactively respecting robots.txt URL exclusions and
filtering for non-permissive, toxic, and personally
identifiable content. To mitigate risks of memorization, we
adopt the Goldfish objective during pretraining, strongly
suppressing verbatim recall of data while retaining
downstream task performance. The Apertus models also expand
multilingual coverage, training on 15T tokens from over 1800
languages, with ~40% of pretraining data allocated to
non-English content. Released at 8B and 70B scales, Apertus
approaches state-of-the-art results among fully open models
on multilingual benchmarks, rivalling or surpassing
open-weight counterparts. Beyond model weights, we release
all scientific artifacts from our development cycle with a
permissive license, including data preparation scripts,
checkpoints, evaluation suites, and training code, enabling
transparent audit and extension.
Bio:
MARTIN JAGGI is an associate professor at EPFL, where he is
leading the Machine Learning and Optimization Laboratory.
Before
that, he was a post-doctoral researcher at ETH Zurich, at
the Simons Institute in Berkeley, and at École Polytechnique
in Paris. He has earned his PhD in Machine Learning and
Optimization from ETH Zurich in 2011, and a MSc in
Mathematics also from ETH Zurich.