Since all these come together in a LAMP package, which you can download and install, they call it a stack.
Below is one comment i came across in net
---
The reason they call it a stack is because each level derives off it's base layer. Your Operating system, Linux, is the base layer. Then Apache, your web daemon sits on top of your OS. Then your database stores all the information served by your web daemon, and PHP (or any P* scripting language) is used to drive and display all the data, and allow for user interaction.
Don't be overly concerned with the term 'stack'. People really just mean software suite or bundle, but you're using it just fine I am sure as you are.
Other terms
----
WAMP, "Windows, Apache, MySQL, and PHP", an application server platform.WAMP
LYME
http://en.wikipedia.org/wiki/LYME_(software_bundle)
LYME and LYCE are solution stacks composed entirely of free and open-source software to build high-availability heavy duty dynamic web pages. The stacks are composed of:
- Linux, the operating system;
- Yaws, the web server;
- Mnesia or CouchDB, the database;
- Erlang, the functional programming language.
