Critical difference for interoperability: Yii3 and Spiral lead with full PSR compliance. Symfony has excellent support with some bridges. Laravel has selective compliance. CodeIgniter has minimal compliance.
| PSR Standard | Symfony 7.3 | Laravel 11 | Spiral 3.15 | CodeIgniter 4.6 | Yii 3 |
|---|---|---|---|---|---|
| PSR-1: Basic Coding | ✅ Full | ✅ Full | ✅ Full | ✅ Full | ✅ Full |
| PSR-2/12: Coding Style | ✅ Full (PSR-12) | ✅ Full (PSR-12) | ✅ Full (PSR-12) | ✅ Full (PSR-12) |
