From reading the tea-leaves and lurking in the php newsgroups, something tells me that PHP5 will be released within the next two weeks.

Now it's an axiom in the software industry that patience is a virtue (certainly a virtue that's more useful than virginity anyway). Patience is good because we always need time to shake out the bugs hiding in the hairy parts of the code. PHP4 became stable around 4.0.6, a whopping 13 months after the initial release. And PHP3 became stable around 3.0.6, which was 6 months later.

Given such a limited sample size, I would hazard to guess that PHP5 will become rock-solid sooner than PHP4, perhaps within 5-8 months. This is because the transition from PHP3 to PHP4 was a complete rewrite, while PHP5 retained large chunks of stable PHP4 code.

PHP3 was done by Zeev and Andi when they were serious students, and PHP3 was their college project. The fact that PHP3 became stable so quickly is a testament to the fact that it's easier to code when you are young and don't have a life.

Of course PHP still remains unstable in multi-threaded mode, because the extensions that sit on top of PHP are riddled with synchronization bugs where even angels fear to multi-thread. Fortunately these PHP extensions work fine on robust fastcgi and pre-fork mode web servers, otherwise we would be speculating about whether PHP5 will ever be stable, and not when PHP5 will become stable. Remember that robustness means you never have to say you're sorry, because you can write terrible code and still survive.

Finally, a word of caution. I must admit all predictions are useless, but it is fun speculating, even when you're wrong.