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GPT-OSS, Simply Explained (The Real Architecture of LLMs)
AI, But Simple Issue #73
Edwin Dong & Lalit Julapalli
October 20, 2025
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GPT-OSS, Simply Explained (The Real Architecture of LLMs)
AI, But Simple Issue #73
In August 2025, OpenAI made a surprising announcement: they were going to release open-source and fully open-weight models.
They ended up releasing two new state-of-the-art models under the gpt-oss family, with a larger variant (gpt-oss-120b) and a smaller one (gpt-oss-20b), all available under an Apache 2.0 license.
For a company that had spent years building its reputation on proprietary, API-only models like GPT-4, releasing rivalling open-source models seemed far away.
This marks OpenAI's first large, fully open-weight release since GPT-2, which may be a signal for what’s to come in terms of collaboration within the AI ecosystem.
