awesome-php.md

@@ -149,4 +149,5 @@ A list of amazingly awesome PHP libraries that you should consider using (and so
 * [How Big Are PHP Arrays (And Values) Really?](http://nikic.github.com/2011/12/12/How-big-are-PHP-arrays-really-Hint-BIG.html) - An article about array internals.
 * [The PHP Ternary Operator. Fast or Not?](http://fabien.potencier.org/article/48/the-php-ternary-operator-fast-or-not) - An article ternary performance.
 * [On PHP 5.3, Lamda Functions and Closures](http://fabien.potencier.org/article/17/on-php-5-3-lambda-functions-and-closures) - An article about lambda functions and closures.
+* [Understanding OpCodes](http://blog.golemon.com/2008/01/understanding-opcodes.html) - An article about opcodes.
 * PHP Source Code for Developers: [1](http://blog.ircmaxell.com/2012/03/phps-source-code-for-php-developers.html) [2](http://nikic.github.com/2012/03/16/Understanding-PHPs-internal-function-definitions.html) [3](http://blog.ircmaxell.com/2012/03/phps-source-code-for-php-developers_21.html) [4](http://nikic.github.com/2012/03/28/Understanding-PHPs-internal-array-implementation.html)