# Apache 2.0 License
The Apache License 2.0 is a permissive open source license published by the [[Apache Software Foundation (ASF)]] in 2004. It allows users to use, modify, and distribute the software for any purpose—including proprietary use—while providing an explicit patent grant and requiring preservation of copyright notices and disclaimers.
Unlike the [[GNU General Public License (GPL)]], Apache 2.0 doesn't require derivative works to be open source (no copyleft). It's popular in enterprise environments because it's business-friendly, legally clear, and compatible with [[GPLv3 License|GPLv3]]. The explicit patent grant protects users from patent litigation by contributors.
## Key Features
- **Permissive**: No copyleft, proprietary use allowed
- **Patent grant**: Contributors grant patent licenses
- **Attribution**: Must retain copyright/license notices
- **State changes**: Must note significant modifications
- **No trademark rights**: Doesn't grant trademark use
## Apache 2.0 vs MIT/BSD
| Aspect | Apache 2.0 | MIT/BSD |
|--------|------------|---------|
| Patent grant | Explicit | None |
| Length | Longer, detailed | Very short |
| Attribution | Required | Required |
| Enterprise use | Preferred | Common |
## Notable Apache 2.0 Projects
- **Android** (AOSP)
- **Kubernetes**
- **TensorFlow**
- **Apache HTTP Server**
- **Rust** (dual MIT/Apache)
- **Swift**
## References
- https://www.apache.org/licenses/LICENSE-2.0
- https://en.wikipedia.org/wiki/Apache_License
## Related
- [[MIT License]]
- [[BSD License]]
- [[GNU General Public License (GPL)]]
- [[Functional Source License (FSL)]]
- [[Open Source]]
- [[Open Source Initiative (OSI)]]
- [[Apache Software Foundation (ASF)]]