However, there are still too many things flawed to consider PHP for a serious project:

http://maurus.net/resources/programming-languages/php/

There are projects out there large and small that use it, but it cannot be helped. Those developers will either know enough to work around PHP’s flaws and limitations or else remain ignorant of them. That still doesn’t prove that PHP is still relevant.

Name spaces are just one small example. How about lexical scoping?

http://www.sitepoint.com/blogs/2007/12/23/lexical-scope-to-appear-in-php/

There are only patches to implement it — another fundamental feature to be tacked on. Not to mention that the example code on that page is horrid to look at and very difficult to read. It may also be incompatible with PHP5’s object system as pointed out by one commenter.

It’s certainly not a dead language by any stretch, but it is becoming very obsolete.