> Because a framework is basically a set of libraries that work together to help you get to a certain goal. In theory, sure, and as another poster said that's

> Because a framework is basically a set of libraries that work together to help you get to a certain goal. In theory, sure, and as another poster said that's exactly what the PHP-FIG (PHP Framework Interoperation Group) have achieved over the past year or two. However, in practice, the big frameworks that most developers and employers use give you much more than just a set of easily plugged together libraries, typically enough more that you end up building software on-top of that framework, and extracting your product out onto another or swapping a library out becomes nigh-on impossible.