Those complaining about migration from PHP4 do have a small gripe but the fact is that the developers gave people ample time to plan for the end of PHP4 support. PHP5 has been out since 2004 - it's 5 years later!!! Since PHP is a young language that was built for a totally different purpose than what it is used for today, things like breaking backwards compatibility are necessary for its maturation. Just look at a description of Rasmus' original implementation of PHP (
Personal Home Page) and you'll see this language needed to be altered for the heavy lifting it tries to do today. The culture had to and must continue to change. Unlike Java or other robust languages, PHP was created from the ground up to be Christina Aguilera...er, I meant quick and dirty.
PHP4 which was the first version of PHP that was really ready for widespread use was released in 2000 with much of the cruft that made PHP/FI 2 swiss cheese when it comes to security. Also, it had hacked-on OO syntax and even though you could create your own objects, it was more about OO syntax than function. PHP5 changed a lot of key things, especially those having to do with objects, mysql, new extensions, and quite a few variables.
The changes between PHP4 & PHP5 weren't that big of a deal as some made them out to be though. Its not like it went from -> to
.dot syntax. Things are much less painful this time around going from PHP5 to PHP6. They are mainly doing some housekeeping, unifying some parts of the most used pieces, making it play nicely with the world's many languages, and shaving off the stuff that causes the most security problems. No biggie. The security benefits, speed, built-in caching (APC), & bug fixes give people added incentive to upgrade.
-PHP Expert