DeepSeek's V4.1-Flash Leads This Week's Open Source Model Signals
2026-09-13 · published 23:35 UTC · research report
A single tracking run finds one open-source model backed by two independent sources, one single-sourced lunar science model, and a widely discussed coding model whose open-source status is unconfirmed.
DeepSeek-V4.1-Flash: the most corroborated model this week
DeepSeek's V4.1-Flash appeared as a live repository on Hugging Face, with a model card offering instructions for running it through various libraries, inference providers, notebooks, and local apps. [S3]
A separately hosted, community-maintained quantized version of the model notes that as of September 10, 2026, no inference engine had yet fully implemented support for its format — though vLLM had open pull requests filed "the morning the model dropped," and SGLang had already merged a cookbook with initial support. Because two distinct fetched pages report on this same model, DeepSeek-V4.1-Flash is the only release in this week's tracking to clear signal-level confidence rather than resting on a single unconfirmed report. Neither source states an explicit release date outright; the timing is inferred from when engine support work began rather than from a dated announcement. [S3] [S4]
NASA and IBM's Lunar Foundation Model: unconfirmed, single source
IBM and NASA jointly announced the open-source release of a Lunar Foundation Model on September 10, 2026, describing it as one of the first publicly available foundation models for scientific exploration of the Moon. This claim currently rests on a single fetched source — IBM's own newsroom announcement — so it should be treated as unconfirmed until an independent source corroborates it. [S1]
Cognition's SWE-2 draws heavy discussion, but isn't confirmed open source
A Hacker News thread about Cognition's new SWE-2 model, posted under a title claiming it rivals models called Fable 5.1 and GPT-Astra, gathered 443 points and 190 comments within two days — a sign of active developer interest in new coding-model releases this week. The thread does not establish whether SWE-2 is open source, so it is not included in this week's open-source model ranking and should be read only as a general community-interest signal, not a confirmed open-source release. [S2]