[francislavoie]

PSR-7 is framework agnostic, but not all PHP apps are PSR-7 ready. E.g. WordPress. That's the distinction. You can't just point Roadrunner at any PHP script or legacy PHP app and expect it to just run, but you can with FrankenPHP.

[rustatian-me]

Sure, RR can't serve legacy PHP or WordPress (actually can, but that's not released yet), that's true. But the modern PHP ecosystem leaves lesser and lesser such a non-compatible scripts ;)