| db_installer_object | Returns a database installer object. |
| db_run_tasks | Ensures the environment for a Drupal database on a predefined connection. |
| drupal_check_module | Checks a module's requirements. |
| drupal_check_profile | Checks an installation profile's requirements. |
| drupal_current_script_url | Returns the URL of the current script, with modified query parameters. |
| drupal_detect_baseurl | Detects the base URL using the PHP $_SERVER variables. |
| drupal_detect_database_types | Detects all supported databases that are compiled into PHP. |
| drupal_get_database_types | Returns all supported database installer objects that are compiled into PHP. |
| drupal_get_installed_schema_version | Returns the currently installed schema version for a module. |
| drupal_get_schema_versions | Returns an array of available schema versions for a module. |
| drupal_install_fix_file | Attempts to fix file permissions. |
| drupal_install_mkdir | Creates a directory with the specified permissions. |
| drupal_install_profile_distribution_name | Loads the installation profile, extracting its defined distribution name. |
| drupal_install_system | Installs the system module. |
| drupal_load_updates | Loads .install files for installed modules to initialize the update system. |
| drupal_requirements_severity | Extracts the highest severity from the requirements array. |
| drupal_requirements_url | Returns a URL for proceeding to the next page after a requirements problem. |
| drupal_rewrite_settings | Replaces values in settings.php with values in the submitted array. |
| drupal_set_installed_schema_version | Update the installed version information for a module. |
| drupal_uninstall_modules | Uninstalls a given list of disabled modules. |
| drupal_verify_install_file | Verifies the state of the specified file. |
| drupal_verify_profile | Verifies an installation profile for installation. |
| install_goto | Sends the user to a different installer page. |
| install_profile_info | Retrieves information about an installation profile from its .info file. |
| st | Translates a string when some systems are not available. |