The ATK Framework is a PHP business framework. It is targeted at developers who wish to focus on business logic instead of coding HTML. ATK provides a complete framework that requires only small amounts of code to get usable applications, while maintaining full flexibility. ATK has a model driven approach, but is 100% customizable.
SMEWebApp is a framework for constructing Web applications for SMEs (small and medium-sized enterprises, companies, institutions, and organizations). It is built on phpWebApp, and it is higher-level and more specific than phpWebApp. It has some components that can be reused in any application (perhaps with small modifications), like hierarchical menus, user authentication, and user administration. The aim of the project is to make Web application construction for SMEs easier than using VB.
With MetaModel, you use a type-safe SQL-like API for querying any datastore. It is a data access framework providing a common interface for exploration and querying of different types of datastores. It isn't a data mapping framework. Instead, it emphasizes abstraction of metadata and the ability to add data sources at runtime, making MetaModel great for generic data processing applications, but less so for applications modeled around a particular domain.