Well, after C++ and Java it's a good idea to actually learn C. It still makes a big part of the world to go around, an it seems hard these days to find programmers who know how to write fast and secure code in C.
from the i'm-told-that's-a-popular-drug dept.
Steve writes "IBM developerWorks has put together a PHP recommended reading list. It provides resources for developers and admins adopting PHP and tackling advanced topics such as building extensions and writing secure code. There's also a list of books and blogs for keeping up with changes to the language itself."