C++ (Gets better only if someone pays me lots of money)
Very good knowledge of
LAMP (Linux Apache MySQL PHP) Environment
Apache/nginx web server configuration
CPANEL/DIRECTADMIN/KLOXO/ISPConfig/Clean Linux Configuration and maintenance with both APACHE and nginx (standalone or as a Reverse Proxy).
Much Experience with MySQL Optimization in large databases (over 10GB)
OpenVZ Server Virtualization
Local/remote server backups, rsync differential backups for various Linux based Web Hosting Control Panel Systems.
Have much experience with hi-demand, hi-traffic websites and experiment with various caching engines including but not limited to: Smarty, Custom PHP file caching, mysql output caching, nginx output caching to RAM through linux tmpfs and memcached with php.