Here is an oldie. I found it when I was cleaning my bookshelf. Is a short reference about Perl 5.6 still usable in 2012 after Perl 5.16.2 has been released? It depends on you usage of such references, do you like to have something on your desks which looks nice, something which avoids that the wind will mess with your sheets so called paper weight? Or do you prefer current references. I am pretty indifferent about such references. The code inside in it will still work, even in 2012. If you are trying to compile stuff from the original K&R C book the current C compilers will probably remove your user account and lock down the root access to the server. In Perl, however, nearly everything still works – starting from the geological stable Perl versions ( (c), mst ) up to the current Perl version. This leads to the question about deprecation of features. Brian d. Foy wrote a nice article about this (Perl 5.12). Make sure to look into the perldelta pod pages, usually a few things are being listed as deprecated from version to version (you already did this,right?).
So I am still indifferent about the book. Keep it or trash it? Maybe it's worth keeping it – to get in touch with the ancients. You decide, what's your opinion about this?