Hao Zhao


2026

Apertus: Democratizing Open and Compliant LLMs for Global Language Environments
Alejandro Hern\'andez-Cano | Alexander H\"agele | Allen Hao Huang | Angelika Romanou | Antoni-Joan Solergibert | Barna P\'asztor | Bettina Messmer | Dhia Garbaya | Eduard Frank \v{D}urech | Ido Hakimi | Juan Garcia Giraldo | Mete Ismayilzada | Negar Foroutan | Skander Moalla | Tiancheng Chen | Vinko Sabol\v{c}ec | Yixuan Xu | Michael Aerni | Badr AlKhamissi | In\'es Altemir Marinas | Mohammad Hossein Amani | Matin Ansaripour | Ilia Badanin | Harold Benoit | Emanuela Boros | Nicholas John Browning | Fabian B\"osch | Maximilian B\"other | Niklas Canova | Camille Challier | Cl\'ement Charmillot | Jonathan Coles | Jan Milan Deriu | Arnout Devos | Lukas Drescher | Daniil Dzenhaliou | Maud Ehrmann | Dongyang Fan | Simin Fan | Silin Gao | Miguel Gila | Mar{\'\i}a Grandury | Diba Hashemi | Alexander Miserlis Hoyle | Jiaming Jiang | Mark Klein | Andrei Kucharavy | Anastasiia Kucherenko | Frederike L\"ubeck | Roman Machacek | Theofilos Ioannis Manitaras | Andreas Marfurt | Kyle Matoba | Simon Matrenok | Henrique Mendon\c{c}a | Fawzi Roberto Mohamed | Syrielle Montariol | Luca Mouchel | Sven Najem-Meyer | Jingwei Ni | Gennaro Oliva | Matteo Pagliardini | Elia Palme | Andrei Panferov | L\'eo Paoletti | Marco Passerini | Ivan Pavlov | Auguste Poiroux | Kaustubh Ponkshe | Nathan Ranchin | Javier Rando | Mathieu Sauser | Jakhongir Saydaliev | Mukhammadali Sayfiddinov | Marian Schneider | Stefano Schuppli | Marco Scialanga | Andrei Semenov | Kumar Shridhar | Raghav Singhal | Anna Sotnikova | Alexander Sternfeld | Ayush Kumar Tarun | Paul Teiletche | Jannis Vamvas | Xiaozhe Yao | Hao Zhao | Alexander Ilic | Ana Klimovic | Andreas Krause | Caglar Gulcehre | David Rosenthal | Elliott Ash | Florian Tram\`er | Joost VandeVondele | Livio Veraldi | Martin Rajman | Thomas C. Schulthess | Torsten Hoefler | Antoine Bosselut | Martin Jaggi | Imanol Schlag
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Open LLMs enable AI practitioners to control development costs by building on an existing foundation for downstream applications. While offering substantial promise, current models often fail to meet the needs of users needing open solutions aligned with responsible AI principles, including data compliance, transparency, and inclusivity. In this work, we present Apertus, a fully open suite of large language models (LLMs) designed to address responsibility shortcomings in today’s open model ecosystem, namely data responsibility and global 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 exclusions and filtering for non-permissive, toxic, and personally identifiable content. To mitigate risks of data memorization, we also adopt the Goldfish objective during pretraining, strongly suppressing verbatim recall of data while retaining downstream task performance. Apertus also drastically expands multilingual coverage, training on 15T tokens from over approximately 1800 languages, with about 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, rivaling or surpassing open-weight counterparts.
Large Language Models (LLMs) achieve strong results on code generation, but single model inference remains brittle on tasks that require iterative refinement. Existing multi agent frameworks improve reliability, yet they often incur substantial token and latency overhead. We introduce PairCoder, a framework that brings pair programming to autonomous LLM collaboration. PairCoder assigns one model to code generation and the other to review, and switches roles when repeated errors suggest that the current interaction has stalled. Across 13 LLMs on HumanEval, PairCoder consistently improves over single model inference. On eight representative backbones, it reaches 91.0% pass@1 and improves over single model inference by up to 20.3% while reducing token usage by 40% to 70% relative to multi agent baselines. Many heterogeneous pairings also outperform both constituent models, suggesting that the framework generalizes across model families. These results position PairCoder as an effective and deployment conscious alternative to heavier multi agent systems.Code is available at https://github.com/yisuanwang/PairCoder

2025

With the success of 2D diffusion models, 2D AIGC content has already transformed our lives. Recently, this success has been extended to 3D AIGC, with state-of-the-art methods generating textured 3D models from single images or text. However, we argue that current 3D AIGC methods still don’t fully unleash human creativity. We often imagine 3D content made from multimodal inputs, such as what it would look like if my pet bunny were eating a doughnut on the table. In this paper, we explore a novel 3D AIGC approach: generating 3D content from IDEAs. An IDEA is a multimodal input composed of text, image, and 3D models. To our knowledge, this challenging and exciting 3D AIGC setting has not been studied before. We propose the new framework Idea23D, which combines three agents based on large multimodal models (LMMs) and existing algorithmic tools. These three LMM-based agents are tasked with prompt generation, model selection, and feedback reflection. They collaborate and critique each other in a fully automated loop, without human intervention. The framework then generates a text prompt to create 3D models that align closely with the input IDEAs. We demonstrate impressive 3D AIGC results that surpass previous methods. To comprehensively assess the 3D AIGC capabilities of Idea23D, we introduce the Eval3DAIGC-198 dataset, containing 198 multimodal inputs for 3D generation tasks. This dataset evaluates the alignment between generated 3D content and input IDEAs. Our user study and quantitative results show that Idea23D significantly improves the success rate and accuracy of 3D generation, with excellent compatibility across various LMM, Text-to-Image, and Image-to-3D models. Code and dataset are available at https://idea23d.github.io/.
As large language models (LLMs) advance across diverse tasks, the need for comprehensive evaluation beyond single metrics becomes increasingly important.To fully assess LLM intelligence, it is crucial to examine their interactive dynamics and strategic behaviors.We present LLMsPark, a game theory–based evaluation platform that measures LLMs’ decision-making strategies and social behaviors in classic game-theoretic settings, providing a multi-agent environment to explore strategic depth.Our system cross-evaluates 15 leading LLMs (both commercial and open-source) using leaderboard rankings and scoring mechanisms. Higher scores reflect stronger reasoning and strategic capabilities, revealing distinct behavioral patterns and performance differences across models.This work introduces a novel perspective for evaluating LLMs’ strategic intelligence, enriching existing benchmarks and broadening their assessment in interactive, game-theoretic scenarios.The benchmark and rankings are publicly available at https://llmsparks.github.io/.

2024

The Mixture of Experts (MoE) for language models has been proven effective in augmenting the capacity of models by dynamically routing each input token to a specific subset of experts for processing. Despite the success, most existing methods face a challenge for balance between sparsity and the availability of expert knowledge: enhancing performance through increased use of expert knowledge often results in diminishing sparsity during expert selection. To mitigate this contradiction, we propose HyperMoE, a novel MoE framework built upon Hypernetworks. This framework integrates the computational processes of MoE with the concept of knowledge transferring in multi-task learning. Specific modules generated based on the information of unselected experts serve as supplementary information, which allows the knowledge of experts not selected to be used while maintaining selection sparsity. Our comprehensive empirical evaluations across multiple datasets and backbones establish that HyperMoE significantly outperforms existing MoE methods under identical conditions concerning the number of experts. Our code is publicly available at https://github.com/Bumble666/Hyper_MoE

2023

“Artificial general intelligence (AGI) used to be a sci-fi word but recently the surprising general-ization capability of foundation models have triggered a lot of attention to AGI, in both academiaand industry. Large language models can now answer questions or chat with human beings,using fluent sentences and clear reasoning. Diffusion models can now draw pictures of unprece-dented photo-realism, according to human commands and controls. Researchers have also madesubstantial efforts to explore new possibilities for robotics applications with the help of founda-tion models. Since this interdisciplinary field is still under fast development, there is no clearmethodological conclusions for now. In this tutorial, I will briefly go through best known prac-tices that have shown transformative capabilities in several sub-fields. Specifically, there are fiverepresentative paradigms: (1) Using foundation models to allow human-friendly human-car in-teraction; (2) Using foundation models to equip robots the capabilities of understanding vaguehuman needs; (3) Using foundation models to break down complex tasks into achievable sub-tasks; (4) Using foundation models to composite skill primitives so that reinforcement learningcan work with sparse rewards; (5) Using foundation models to bridge languge commands andlow-level control dynamics. I hope these best known practices to inspire NLP researchers.”
Parameter-efficient fine-tuning (PEFT) has shown its effectiveness in adapting the pre-trained language models to downstream tasks while only updating a small number of parameters. Despite the success, most existing methods independently adapt to each task without considering knowledge transfer between tasks and are limited to low-data regimes. To overcome this issue, we propose Prototype-based HyperAdapter (PHA), a novel framework built on the adapter-tuning and hypernetwork. It introduces an instance-dense retriever and a prototypical hypernetwork to generate the conditional modules in a sample-efficient manner. This leads to comparable performance improvements against existing PEFT methods on multi-task learning and few-shot transfer learning. More importantly, when the available data size gets smaller, our method outperforms other strong baselines by a large margin. Based on our extensive empirical experiments across various datasets, we demonstrate that PHA strikes a better trade-off between trainable parameters, accuracy on stream tasks, and sample efficiency. Our code is publicly available at https://github.com/Bumble666/PHA
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