[CentOS] php53 and Fileinfo

I see though:

# rpm -ql php53-common-5.3.3-1.el5 | grep modules
/usr/lib/php/modules
/usr/lib/php/modules/curl.so
/usr/lib/php/modules/fileinfo.so
/usr/lib/php/modules/json.so
/usr/lib/php/modules/phar.so
/usr/lib/php/modules/zip.so

So json and fileinfo are probably built-in now?

Sorry, I'm not very proficient in PHP (and many other things :-)

Regards
Alex