Going META!

Recently i am interested metaobject protocols.
Reading "The Art of the Metaobject Protocol" by Gregor Kiczales, Jim Des Rivieres, Daniel G. Bobrow (MIT Press) was a wonderful experience for me.
Like Alan Kay said: "The Art of the Metaobject Protocol is the best book written in computing in ten years" (Keynote OOPSLA 1997).

In a language based upon metaobject protocols, the language implementation itself is structured as an object-oriented program. This allows the power of object-oriented programming techniques to be exploited to make the language implementation adjustable and flexible. In effect, the resulting implementation does not represent a single point in the overall space of language designs, but rather an entire region within that space.

A metaobject protocol (MOP) is an interpreter of the semantics of a program that is open and extensible. Therefore, a MOP determines what a program means and what its behavior is, and it is extensible in that a programmer (or metaprogrammer) can alter program behavior by extending parts of the MOP. The MOP exposes some or all internal structure of the interpreter to the programmer. The MOP may manifest as a set of classes and methods that allow a program to inspect the state of the supporting system and alter its behaviour. MOPs are implemented as object-oriented programs where all objects are metaobjects.

The the best-known runtime MOP and the most powerful is the one described in the book "The Art of the Metaobject Protocol"; it applies to the Common Lisp Object System (CLOS) and allows full reflection (introspection and intercession) on every entity in CLOS (object, classes, methods, slots) and even on the mechanisms of inheritance, method dispatch, class instantiation and so on.

Even if your not interested in this meta-stuff, you should read this book because you will think differently after that, and you'll look at OO programming from another angle.
So my advice is: go META!