LEMP is a the combination of Linux with Nginx(engine x), MySQL (database software) and PHP to create a viable general purpose web server.

Installation details can be found on the LEMP server puppy thread.

Nginx - web server used for LEMP
XAMPP - web stack using Apache
LAMP - web stack using Apache
Hiawatha - alternative web server.
HiawathaServerMySql - web server and MySql.

LEMP server puppy thread.