"PHP 4 didn't really catch fire in terms of real-world server
support until its first major update, version 4.1. Will the same be
true of PHP 5, the first point release of which is now in its early
"PHP 5.1 Beta 1 has been out for ten days, and Beta 2 has just
become available. Neither of these releases has yet been announced
on php.net, nor has an official list of changes been posted, but if
you're especially curious you can read the detailed breakdown
maintained by the developers..."