Microsoft introduced LUIS (Language Understanding Intelligent Service) as its Natural Language Processing service a few years ago.  I wrote about my use of this in apps here (to provide a more natural and intelligent alternative to mouse navigation: the software suggests next steps for the user)

If you revisit such apps now, you are informed that you need to migrate them to CLU (Conversational Language Understanding) but at present the migration seems to be buggy with repeated errors.  (Please fix this Microsoft).

However the original LUIS apps still seem to work (for now at least).