It’s an abreviation for Linux, Apache, MySQL, PHP. The most common way of putting a data driven page on the internet.

LAMP is an open-source Web development platform that uses Linux as the operating system, Apache as the Web server, MySQL as the relational database management system (RDBMS) and PHP as the object-oriented scripting language. Perl or Python can be substituted for PHP.

The key to the idea behind LAMP is the use of these items together. Although not actually designed to work together, these open source software alternatives are readily and freely available as each of the components in the LAMP stack is an example of Free or Open Source Software (FOSS).