> REST

No. Rails populated a form of REST and everybody likes to pretend everything Rails is REST and there are a ton of frameworks trying to imitate Rails' approach to REST but Rails neither invented REST nor was it the one thing making REST popular. It was a major factor, yes, but claiming this purely as an accomplishment of Ruby is silly.

I would be willing to give Ruby the point for MVC because of ActiveRecord but MVC is not synonymous with REST.

> Many parts of ES.next

Again, no. ES.next is nothing like Ruby. Some of the syntax was influenced by CoffeeScript (nobody doubts that -- in fact, TC39 members have explicitly referenced it on more than one occasion) but the features are neither novel nor unique to Ruby:

* The class syntax is pretty much universal.

* The arrow functions are evidently influenced by CoffeeScript but look nothing like Ruby's lambda literals (which are the closest equivalent in Ruby). I think CoffeeScript's use of that syntax was actually pre-dated by C# but I may be mistaken.

* Template strings have no more in common with CoffeeScript's and Ruby's string interpolation than with the same feature in other languages. In fact, if anything, I'd say the interpolation syntax is borrowed from PHP -- but the backticks certainly aren't taken from any of them.

* Symbols are kinda like Ruby symbols if you tilt your head and squint really hard and then only focus on the name and not what they actually are. Again, the concept is neither novel nor unique to Ruby.

* Destructuring and rest/spread operators -- yeah, again, not unique or novel. Plus I think even Python preceded Ruby on that.

* iterators and generators -- again, closer to Python than to Ruby.

* import/export -- just an extension of the ideas of CommonJS which in turn aren't anything like what Ruby has.

* promises -- no, sorry, not Ruby.

* the object literal extensions -- again, not Ruby. Ruby doesn't even have object literals in the sense JS does (which is okay, it doesn't have prototypal inheritance either).

> Front-end build tools

No, seriously not. Yes, rake pre-dates grunt and gulp by a fair amount (as well as jake and other JS-based tools barely anyone seems to use anymore). But it certainly didn't invent them nor was the biggest factor in popularizing them. A lot of build tools before the Ruby (and now JS) toolchains came along were built in things like Java, in addition to the various less formalized build tools written in Python or simply bash.

> CSS pre-compilation

I may give you that. Less pre-dates Sass but started as a Ruby gem. Of course neither of them invented CSS minification and there were attempts at generating CSS before. Compass probably took the crown, though, even though front-end tools in generally have moved on to the Node ecosystem, which seems more appropriate for tools primarily concerned with JS (rather than Ruby, Java or bash).

> JS transpilation

Not really. Java-to-JS transpilation was the original hotness that opened up people to the idea. It was followed by various attempts to port other languages to JavaScript. I agree that CoffeeScript is the first one that gained major traction in the startup scene -- although most teams seem to have realised that the drawbacks aren't really worth it (not just the transpilation but the entire part where everyone has to learn a new language on top of a solid understanding of JS itself).

Yes, CoffeeScript was an important step in the evolution of JS but so were DHTML, pop-unders, JSS and animated mouse cursors and status bars -- and everyone agrees those were a bad idea.

The Ruby community is very vocal and self-important but it's neither as uniquely innovative nor as much of an influence as its members like to make it out to be. If PHP is the kindergarden of programming languages, Ruby is the angsty teenager complaining about how nobody understands them and writing blog posts about their deep insights gained from flipping through Atlas Shrugged.