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.