Small, clean, well-commented codebase. Top-to-bottom table column aliasing. Natural, model-oriented extension of Kohana's Query Builder. Extensible field architecture.

HMVC is a collection of traditional MVC triads operating as one application. Each triad is completely independent and can execute without the presence of any other. All requests made to triads must use the controller interface, never loading models or libraries outside of their own domain. The triads physical location within the hosting environment is not important, as long as it is accessible from all other parts of the system. The distinct features of HMVC encourages the reuse of existing code, simplifies testing of disparate parts of the system and ensures that the application is easily enhanced or extended.

Kohana 3 Guide