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Keeping up with open source model development

by Dick Blankvoort
10 June 2025

At the European Open Source AI Index, we seek to provide a comprehensive overview of transparency within the open-source AI landscape. A significant challenge involved in this is deciding which models to include and which to exclude. Even a cursory glance into the AI space reveals a wealth of AI models competing for recognition, and our index can only include so many before growing cluttered.

In this blog post, we seek to highlight one aspect we consider when deciding what makes a model a candidate for inclusion; its perceived level of diversification. By 'diversification', we mean the degree to which a model is able to set itself apart from another model and prove that it is an innovation in its own right rather than a patch on top of an existing model. By examining this aspect, we aim to highlight some potentially interesting initiatives which might not be captured by our index, as well as provide insight into some more obscure techniques used in AI technologies.

Incremental and innovative model development

Let's start with some ground work. There are many reasons why a model might be considered too similar to another model to warrant inclusion. A model might be insufficiently innovative to warrant inclusion, it might be an adaption of a different model to a different architecture, or it might be primarily a fine-tune based on a dataset.

Fine-tunes based on a dataset

There are quite a few models in our dataset which are not included due to primarily revolving around fine-tuning a model on a dataset. It could, for instance, be that these models employ a novel fine-tuning approach or show significant innovation in a dataset, however in the end the emphasis with them lies not so much on the model but rather on how the model was created. These models are usually not intended to be used in a practical setting, and so we do not include them in our overview.

Their lack of inclusion is certainly not to say that these models do not deliver major innovation. For instance, the various Airoboros models together represent a significant effort to tune the well-crafted Airoboros dataset, which has been subsequently used in the training of at least 350 different AI models. In these models we see great potential for technological innovation, and we would encourage researchers to adopt them.

Adaptions to different hardware/architectures

There are also a few models we record which are designed to transplant an existing model to a different hardware or architecture. Notable models here are AMD's models trained on AMD hardware, Amazon's FalconLite, and Snowflake's Llama-3.1-SwiftKV. While such efforts are certainly commendable, they do not warrant separate entries in the index.

In general, these models do represent a good effort towards exploring the benefits of running models in different forms and under different architectures. Exploring different hardware solutions has the potential to disrupt existing monopolies in the AI hardware space, and exploring models within the context of alternative architectures has the opportunity to lead to great performance improvements.

Not enough index-relevant innovation

Lastly, there are models which simply do not provide enough index-relevant innovation to qualify for inclusion in our overview. The word index-relevant is key here, as such models may still deliver plenty of innovation in their own right. Notable models in this category are Flan-T5, which though a strict improvement over T5 does not differentiate itself much from it, RecurrentGemma, which is an interesting RNN-based alternative to Gemma, and model merges.

Model merges are a relatively recent category of LLMs which combine (or 'merge') two existing LLMs together. Though the technique approach is highly interesting and worthy of study, the fact that it has thusfar (as far as we can tell) primarily been applied for gaming LLM leaderboards means that we generally discount any models created using the technique.

Where to draw the line

Any entity seeking to catalogue the AI landscape must decide on which models to include, not only our index. LLM arenas, for instance, perpetually face the challenge of deciding which models to compare against each other in order to provide a comprehensive overview. Approaches taken in this differ. While indices such as OpenLM.AI and LMArena.AI seek to provide a curated comparison of models and place emphasis on highlighting models by the greatest innovators, projects such as the Open LLM Leaderboard (archived since March of 2025) attempted to compare every open model submitted.

In general, a curated approach focusing mainly on the largest innovations seems to have won out. This has the advantage of producing leaderboards that can highlight the most well-known innovations within the AI space. A disadvantage is that many lesser-known models within the open-source AI space may remain somewhat obscure.

Conclusion

The true extent of open-source AI will always reach beyond the scope of our index, and so we would encourage readers to explore the space independently whenever possible. A good start here are the models listed above. What we offer in the Open Source AI Index is a carefully curated, scientifically based selection that provides the best view of model openness. As the field evolves, so too will our criteria. We invite the community to engage with us in shaping a more transparent and inclusive future for open-source AI.

Supported by the Centre for Language Studies and the Dutch Research Council. Website design & development © 2024 by BSTN. This version of the index generated 23 Jul 2025, website content last updated 23 Jul 2025.