PECL runkit extension
Runkit extension for PHP
For all those things you.... probably shouldn't have been doing anyway....
The Runkit extension is designed to allow you to change a PHP function definition at runtime. Both user-defined and internal functions can be redefined.
This behaviour is known as 'Monkey patching'. It is not considered a good coding practice, and should be avoided for general use. It is occasionally useful in test scripts, but not in production code.
Download up-to-date versions from http://github.com/zenovich/runkit