L.A.M.P. refers to a toolset consisting of Linux + Apache + MySQL + PHP|Perl|Python|Postgresql... providing a powerful framework for rapid development of robust solutions. Each component is open source and has proven to be enterprise ready.
I just posted a major update to my guide, Install & Configure Apache with PHP, JSP, MySQL, and PHPMyAdmin on Windows 2000/XP. The update includes all the latest versions of Apache, PHP, JSP, MySQL, and PHPMyAdmin. There's been a lot of great feedback on the original post.