Apache 2.0
Apache 2.0 is a permissive free software license that guarantees users the right to use, modify, distribute and commercially deploy any licensed software without needing the copyright holder’s permission.
Key Features of Apache 2.0 License
- Permissive Licensing: Allows for both proprietary and open-source derivative works.
- No Copyleft: Does not require derivative works to be distributed under the same license.
- Patent Protection: Grants a patent license from contributors to users, protecting against patent trolls.
Recent Adoption by Google Gemma 4
- Gemma 4 Open-Weight Models: Launched in 2026 with Apache 2.0 licensing (clip).
- Capabilities Enhancements: Significant advancements over the Gemma series, emphasizing developer freedom and innovation.
- Four Distinct Models: Includes a variety of special
Other Open-Source Projects
- Kitten TTS by Kitten ML: Open-source text-to-speech framework with ultra-lightweight models (smallest under 25MB) and CPU optimization for edge/browser applications. Video Review
2026 04 14 CPU optimised TTS Kitten AI Sam Witteveen channel