With the first two in particular, you just won’t be able to leverage the full power of the plugin. Assuming that you’re running apache on a Debian/Ubuntu machine, use the following line to enable memcached:
sudo apt-get install memcached php5-memcache
If you’re running CentOS (specifically the yum package manager), use:
sudo yum install memcached php5-memcache
Restart apache:
/etc/init.d/apache2 restart
And recheck the compatibility. You should see some changes ??