Zend is the new optimised scripting engine for PHP4 which is due out next month. This article describes some of the architecture and thoughts behind the new version. Interesting to see that on WIN32 they're adding ISAPI and COM support in direct competition to ASP. Reliability has always been ASPs weakest point, it's great for Intranet scenarios where the hit rate is fairly low and you can reboot without worrying about your customers, but in an Internet situation something like PHP has to be the first choice.