Mellum-4b-base is JetBrains' first open-source large language model (LLM) optimized for code-related tasks.

Mellum is the most popular Self-Hosted alternative to Kiro.
- Mellum is Free and Open Source
The best alternative to Kiro is Mellum, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Kiro and three of them are so hopefully you can find a suitable replacement. Other interesting alternatives to Kiro are Mistral Code and JetBrains Junie.
Mellum-4b-base is JetBrains' first open-source large language model (LLM) optimized for code-related tasks.

Mellum is the most popular Self-Hosted alternative to Kiro.
Lightning-fast completions, deep code understanding, and agentic software engineering—right where you work.




You think it, Junie helps make it happen – right in your IDE. Available on IntelliJ IDEA, PyCharm, WebStorm and .



