You mean MySQL.
Does the installation of PHP on FC3 come with the PHP_MSSQL already installed?
It depends on the installation you opted for. If it is not installed you can easily get it through yum or apt-get. I am almost always on slackware so can't give you much insight into this. One way to check it to if mysql is installed it to try and locate it
$ locate mysql
Secondly, if mysql is installed you can do this to see if PHP recognizes it...
create a file phpinfo.php
edit the file and put the following lines
and put this file in to your webserver root directory...open up your browser and point it to the file location...
Hope this helps...