The Generator meta tag in output shows the CMS software and version used to generate the page.

<meta name="Generator" content="Drupal 7 (http://drupal.org)" />

Some sites choose to remove or replace this from output. When considering doing so, note Hide, obscure, or remove clues that a site runs on Drupal.

Module-based solutions

Drupal generator meta tag can be hidden using the following modules:

  1. Remove HTTP Headers will remove the "Generator" meta tag when it is configured to remove Drupal's X-Generator HTTP header.
  2. Remove Generator will remove the "Generator" meta tag specifically.
  3. If you use the popular Metatag module, then you can edit the Drupal generator meta tag using that module (screenshots: 1, 2, 3).

Removing or replacing Generator using templates (Drupal 7)

The same can also be done using template.php. Put in the below code in template.php file. If you already have _html_head_alter() defined, add the below code in that function.

To replace the Generator meta tag

/**
* Implements hook_html_head_alter().
*/
function YOUR_THEME_html_head_alter(&$head_elements) {
  // Replace Drupal generator meta tag.
  // Use this if you want to replace the Drupal 7 Generator meta tag.
  $generator = 'Enter your text here';
  $head_elements['system_meta_generator']['#attributes']['content'] = $generator;
  if (isset($head_elements['system_meta_generator']['#attached']['drupal_add_http_header'][0][1])) {
    $head_elements['system_meta_generator']['#attached']['drupal_add_http_header'][0][1] = $generator;
  }
}

To remove the Generator meta tag

/**
* Implements hook_html_head_alter().
*/
function YOUR_THEME_html_head_alter(&$head_elements) {
  // Remove Drupal generator meta tag.
  // Use this if you want to remove the Drupal 7 Generator meta tag.
  if (isset($head_elements['system_meta_generator'])) {
    unset($head_elements['system_meta_generator']);
  }
}