Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/install.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * @file
+ * Initiates a browser-based installation of Drupal.
+ */
+
+// Change the directory to the Drupal root.
+chdir('..');
+
+/**
+ * Global flag to indicate the site is in installation mode.
+ *
+ * The constant is defined using define() instead of const so that PHP
+ * versions prior to 5.3 can display proper PHP requirements instead of causing
+ * a fatal error.
+ */
+define('MAINTENANCE_MODE', 'install');
+
+// Exit early if running an incompatible PHP version to avoid fatal errors.
+// The minimum version is specified explicitly, as DRUPAL_MINIMUM_PHP is not
+// yet available. It is defined in bootstrap.inc, but it is not possible to
+// load that file yet as it would cause a fatal error on older versions of PHP.
+if (version_compare(PHP_VERSION, '5.4.5') < 0) {
+  print 'Your PHP installation is too old. Drupal requires at least PHP 5.4.5. See the <a href="https://www.drupal.org/requirements">system requirements</a> page for more information.';
+  exit;
+}
+
+// Start the installer.
+$class_loader = require_once 'autoload.php';
+require_once __DIR__ . '/includes/install.core.inc';
+install_drupal($class_loader);