Quoting the talk abstract (http://www.curry-on.org/2017/sessions/reflex-reactive-progra...):
> Reflex is a new programming language for reactive programming developed at Facebook. It has many interesting characteristics, mixing OO and functional programming, it allows rapid development of applications with “spreadsheet semantics.
EDIT: to clarify: that's literally all I found. (I dislike videos so much I had missed that abstract is also on Youtube).