Amy Brown and Greg Wilson, editors of The Architecture of Open Source Applications: Elegance, Evolution, and a Few Fearless Hacks(Lulu.com, 2011, 978-1-257-63801-7), have placed their entire volume of essays online under a Creative Commons license.

It's a collection of essays about the architecture of some familiar software products ...

Read more at :

Java Code Geeks : The Architecture of Open Source Applications