Even after all of this talk about functional concepts not being the best in terms of raw speed, it can still be quite helpful to utilize them in JavaScript. There are many languages out there that are not purely functional and all of these give us the ability to utilize the best ideas from many paradigms. Languages such as F# and Scala come to mind. There are a few ideas that are great when it comes to this style of programming and we can utilize them in JavaScript with built-in concepts.