# JetBrains Releases Mellum2.1: A 12B MoE Open Model for Coding Agents

> Source: <https://www.marktechpost.com/2026/10/08/jetbrains-releases-mellum2-1-a-12b-moe-open-model-for-coding-agents/>
> Published: 2026-10-08 16:17:35+00:00

JetBrains released Mellum2.1, an Apache 2.0, 12B mixture-of-experts thinking model with 2.5B active parameters. RL in real repositories lifted its SWE-bench Verified score from 2.0 to 47.0.

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