According to this posting from PHP Magazine, Andi Gutmans has been quoted as saying "With PHP 5.0, it’s easier for the Web scripting language to sit in the enterprise alongside the rest of the infrastructure. Unlike the previous version 4.0, delivered in 2000, 5.0 supports object-oriented programming, with features such as multiple inheritance and exception handling".

The full story over at SDTimes talks more about their (Zend) effort to extend PHP's object-oriented coding. They're seeking to create a seamless integration from PHP to the outside world, including .NET/COM files as well as XML files treated as if they were native PHP objects.

The rest of the story talks about some of the Zend software, including Studio 3.5 and the Performance Suite 4.0.