ckeditor_menu in core/modules/ckeditor/ckeditor.module
Implements hook_menu().
file_menu in core/modules/file/file.module
Implements hook_menu().
filter_menu in core/modules/filter/filter.module
Implements hook_menu().
layout_menu in core/modules/layout/layout.module
Implements hook_menu().
system_menu in core/modules/system/system.module
Implements hook_menu().
views_menu in core/modules/views/views.module
Implement hook_menu().
views_ui_menu in core/modules/views_ui/views_ui.module
Implements hook_menu().