Run php -version to get your current PHP version. At the time of this post, the current version on RHEL 6 is PHP 5.3.3. Download the corresponding PHP source from: http://www.php.net/releases/
Unpack the source and navigate to ext/sqlite3/, then build and install the plugin.
tar xvfz php-5.3.3.tar.gzEdit /etc/php.d/sqlite3.ini and add:
cp config0.m4 config.m4
extension=sqlite3.soRestart Apache and you should now be able to use sqlite from PHP. To confirm, look at phpinfo() and you should see information about the sqlite3 plugin.