Short for Linux, Apache, MySQL and PHP, an open-source Web development platform, also called a Web stack, that uses Linux as the operating system, Apache as the Web server, MySQL as the RDBMS and PHP as the object-oriented scripting language. Perl or Python is often substituted for PHP.

The key to the idea behind LAMP, a term originally coined by Michael Kunze in the German magazine c't in 1998, 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).

LAMP has become a de facto development standard. Today, the products that make up the LAMP stack are included by default in nearly all Linux distributions, and together they make a powerful web application platform.

The original LAMP acronym has spawned a number of other, related acronyms that capitalize on the main focus of the original combination of technologies to provide feature rich Web sites. Some of these related Web stacks include LAPP, MAMP, and BAMP.