Please see my site message that I just added at the top of the site. I will be leaving this up here indefinitely as I will be making the switch from even the writing of PHP 4 usable classes by the February 5, 2008 deadline. Of course, if there is a class out there that I find useful to incorporate into something I am working on, fine, I'll use it, but not if it does not also work on PHP 5.2. The point is that to be true to OOP coding concepts, I may end up writing something which will not work on PHP 4 and it will be just too bad. Developers have to take a stand and I am taking it personally for myself.
