In a new post to his blog, Tobias Schlitt takes a look at frameworks - no, not any specifiy ones - and defines more of what a framework is and how you can create something that fits into this "more correct" structure.

I attended the talk Framework? No thank you, I will use my own!, this week at IPC 2009 SE. The idea of the session was to get a discussion running about if you should use one of the many existing OSS PHP frameworks out there, or if you go better with building one on your own. [...] The result was quite obvious for many reasons already beforehand: Use an OSS framework! While I fully agree with this result, I stated a somewhat controversial thesis right at the beginning of that talk, mainly to get the discussion running.

Tobias looks at the official definition (via Wikipedia) and looks at how that compares to the more specific definition of a software framework. He talks about creating a framework - not from scratch but possibly standing on the shoulders of another OSS framework.