Functions in the Safer API provide any application that starts programs from external sources the ability to query security policy for approval before an executable is started. These functions can be called before loading and running an executable or active content. Type of applications where the Safer API is useful include applications that handle attachments (such as mail clients and instant messengers that can transfer files) and script interpreters. Support for functions in the Safer API begin with Windows XP. For more information, see Safer Functions.