I've seen the word 'React' showing up lot after Facebook released their React Javascript library. Is the that library is somehow related to what you are referri

I've seen the word 'React' showing up lot after Facebook released their React Javascript library. Is the that library is somehow related to what you are referring to? I don't do any web programming, so can you explain simple what it means by 'react' or 'react like'? What is Reactive programming?