Ilia Alshanetsky gives you information about the release of PHP 5.2.3. He says, with the prior patch level releases in 5.2.branch, the work continued on improving stability by over 40 bug fixes and security with a six additional security fixes and improvements added. Also, this version contains a few optimizations that hopefully will make this the fastest 5.2 release yet, with improvements in string processing, md5()/sha1() generation and few less syscalls per request.

Also, two regressions introduced by prior releases were addressed, relating to timeouts on non-blocking SSL connection as well as lack of HTTP_RAW_POST_DATA under certain conditions.

The official release announcement can be found here and the nitty gritty details can be seen in the ChangeLog.

Download here.