Models & ProductsBrief
JetBrains releases Mellum2.1 open mixture of experts model for coding agents
JetBrains has launched Mellum2.1, an open 12 billion parameter mixture-of-experts model designed to power software development agents.
FTMQ SI, written by our newsroom0 views
JetBrains has released Mellum2.1, an open mixture-of-experts model designed for coding agents, MarkTechPost and Tech Insider reported. The model is released under an Apache 2.0 open-source licence and contains 12 billion total parameters, with 2.5 billion active parameters during inference. [1][2]
According to MarkTechPost, JetBrains used reinforcement learning inside real software repositories during training. This training approach improved the performance of the model on the SWE-bench Verified benchmark, raising its score from 2.0 percent to 47.0 percent. [1]
AI-assisted software development uses large language models and software agents to help programmers write source code, debug, test, and generate documentation. The approach can increase the speed of software delivery, though it carries risks regarding code quality. [4]
In short
- JetBrains released Mellum2.1 under an Apache 2.0 open licence.
- Mellum2.1 features 12 billion total parameters with 2.5 billion active parameters.
- Reinforcement learning in real repositories raised its SWE-bench Verified score to 47.0.
Sources
Every paragraph above points to the numbered items it rests on. Read the originals here.
- [1]JetBrains Releases Mellum2.1: A 12B MoE Open Model for Coding AgentsMarkTechPost, 9h ago (the report this story comes from)
- [2]JetBrains Mellum 2.1: 12B MoE Model Targets Coding Agents [2026]https://tech-insider.org/, 6h ago
Background
- [3]Xiaomi MiMo on Wikipedia
- [4]AI-assisted software development on Wikipedia
Our newsroom writes these reports with the help of software, from the 4 sources listed and nothing else, and checks them against those sources. Facts can still be wrong or move on; the originals are the record. Spotted a mistake? Write to daniel@monsterkong.com.
More in Models & Products
- Alphabet spinoff Isomorphic Labs seeks funding at forty billion dollar valuation1h ago
- Liquid AI releases open weight multimodal decision models d1 3B and d1 omni 600M1d ago
- OpenAI publishes 722 AI-generated math manuscripts on GitHub1d ago
- Anthropic releases Claude Haiku 5.5 and reduces API pricing1d ago
- Meta and Sierra Partner to Create AI Agent Commerce Standards2d ago
- Mistral AI Releases Mistral Large 4 Model in Public Preview2d ago
Get the day in one email
Reports like this one, the top news of the last 24 hours, every morning. Free, one email a day; readers can comment under every report.
By signing up you agree to our terms and privacy policy. Unsubscribe any time.
Comments
Loading
Join the conversation
Comments are open to readers of our daily email: the top news of the last 24 hours, every morning, free. Sign up and the comment box opens.
Already on the list? Enter the same address and we will send a sign-in link.
By signing up you agree to our terms and privacy policy. Unsubscribe any time.