For future reference…

PHP

1. Download an x64 Thread Safe zip from php.net.
2. Read the note about Visual C++ Redistributable in the sidebar of that download page, and install the one required for your version.
3. Unzip somewhere and add to PATH.
4. Pick a php.ini and adjust as necessary (enabled extensions, etc.).
5. In particular, make sure the following is not commented out:
   extension_dir = "ext"
6. Check that it works:
   php --version

Composer

1. Download the Windows Installer from getcomposer.org.
2. Run the installer..
3. Check that it works:
   composer --version

Apache

1. Download the Apache Win64 zip from apachelounge.com.
2. Read the note about Visual C++ Redistributable above the downloads on that download page, and install the required one.
3. Unzip somewhere and adjust httpd.conf as necessary (paths, enabled modules, etc.).
4. Install as service:
   httpd.exe -k install
5. Start the service.
6. Check that it works:
   start http://localhost

Apache with PHP

1. Add the following to httpd.conf.
   LoadModule php7_module C:/path/to/php/php7apache2_4.dll
   <IfModule php7_module>
       DirectoryIndex index.html index.php
       AddHandler application/x-httpd-php .php
       PHPIniDir "C:/path/to/php"
   </IfModule>
2. Add an index.php to your DocumentRoot for testing, e.g.:
   <?php phpinfo();
3. Restart the Apache service.
4. Check that it works:
   start http://localhost

MariaDB

1. Download a Windows x86_64 MSI Package via mariadb.org.
2. Run the installer.
3. Optionally add some of the following to my.ini under mysqld section:
   ; Only listen on localhost
   bind-address=127.0.0.1
   
   ; Enable logging of queries
   ; (probably bad in production, but very helpful for development debugging)
   general-log=1
   general-log-file=queries.log
   log-output=file
4. Restart the service, if you changed anything in the ini.
5. Check that it works by connecting with HeidiSQL or any other SQL client.