The document discusses the future of HTTP support in CakePHP. It outlines plans to adopt the PSR-7 standard for HTTP message interfaces. PSR-7 support will be introduced as an opt-in middleware stack in version 3.3, and will become the default stack in 3.4. The new stack will provide improved request and response objects, and support for middleware. The transition is designed to be backwards compatible, with deprecation warnings before removing legacy features in CakePHP 4.0.