list_themes in core/includes/theme.inc

Returns a list of all currently available themes.

module_disable in core/includes/module.inc

Disables a given set of modules.

module_enable in core/includes/module.inc

Enables or installs a given list of modules.

update_module_enable in core/includes/update.inc

Helper function to install a new module in Backdrop 1.x via hook_update_N().

_system_update_bootstrap_status in core/modules/system/system.module

Refresh bootstrap column in the system table.