Most of us surely know Moose. It is a solid piece of Perl software powering a lot of modern Perl code. It allows for very expressive definition of object attributes. This expresiveness comes at a cost, nicely explained by Curtis "Ovid" Poe in his blog post. In short: it is not immediately obvious what is the purpose of an attribute and you have to look at the option list to get the idea. In addition to that, the attributes become very verbose if you want to nail their behavior exactly right.
