来源:php.net
the first release candidate of php 5 is finally here! the move from beta stage to rc stage means that php 5 is now feature complete, and is quite stable - stable enough for everyone to start playing with. note that it is still not recommended for mission-critical use.
some of the key features of php 5 include:
the zend engine ii with a new object model and dozens of new features.
xml support has been completely redone in php 5, all extensions are now focused around the excellent libxml2 library (http://www.xmlsoft.org/).
a new mysql extension named mysqli for developers using mysql 4.1 and later. additionally to a functional interface this new extension also includes an object-oriented interface and support for many of mysql's new features such as prepared statements.
sqlite has been bundled with php. for more information on sqlite, please visit their website.
a brand new built-in soap extension for interoperability with web services.
a new simplexml extension for easily accessing and manipulating xml as php objects. it can also interface with the dom extension and vice-versa.
streams have been greatly improved, including the ability to access low-level socket operations on streams.
and lots more...
for changes since beta 4, please consult the changelog.