This file is 61MB, and contains all three packages (A+M+P). It defaults to installing Apache in a root directory, with PHP as a module. It optionally installs MySQL. It also optionally installs phpMyAdmin, Perl, and SQLYog. It also optionally installs documentation for Apache, MySQL, PHP, and phpMyAdmin.

This file is 11MB, and contains only Apache and PHP. It contains their full default installations. Useful if you already have MySQL installed and running.
This is the developer toolkit: the NSIS installer scripts and directories used to create WinLAMP. Fairly well documented. If you are serious about improving this code, visit the sourceforge pages for this project; contact the administrator.