* Descargar PDO y descomprimir
{{{
wget http://pecl.php.net/get/PDO_INFORMIX-1.2.7.tgz
tar -xvf PDO_INFORMIX-1.2.7.tgz
}}}

 * Descargar e instalar
{{{
apt-get install php5-dev
}}}

 * Instalar PDO 
{{{
cd PDO_INFORMIX-1.2.7/
phpize
./configure
make
make install
}}}