Here are a few bits of information I collected at PHP Forum (Nov 9 & 10, 2005):

  • It is estimated than no more than 5% of the servers running PHP have switched to PHP 5 yet
  • PHP 5.0 is a feature release, not a performance release. Therefore it is slower than PHP 4.x. Therefore it makes no sense running apps designed for PHP 4 on PHP 5.0.
  • PHP 5.1 should almost match the performance of PHP 4.4
  • Rasmus will probably migrate Yahoo's servers from PHP 4 to PHP 5 once PHP 5.1 has undergone a few weeks without any major issue.
  • It is extremely painful for everyone to make code that works on PHP 5 as well as PHP 4, especially because you cannot redefine the clone statement in PHP 4 for compatibility.

Okay, that’s all I can recall right now! :P

Comments from long ago:

Comment from: Harry Fuecks

“It is extremely painful for everyone to make code that works on PHP 5 as well as PHP 4, especially because you cannot redefine the clone statement in PHP 4 for compatibility”

Not sure clone is such a big problem (see links below). More of a pain is rewriting code to cope with reference issues see http://phplens.com/phpeverywhere/?q=node/view/214

http://cvs.sourceforge.net/viewcvs.py/wact/wact/framework/util/phpcompat/clone.php?view=auto

http://cvs.sourceforge.net/viewcvs.py/wact/wact/framework/util/phpcompat/clone_php5.php?view=auto

2005-11-24 14-05

Comment from: François Planque

Oh sure there is a workaround, but you gotta admit… it feels really dirty doesn’t it? :>

2005-11-24 14-37