Cloud Apps - Up and Rising
One of the first approaches for a cloud app was, when developers began to use javascript for a complete clientside program, which could be loaded from a server. This hat the advantage, that no more requests would need to be made afterwards, or they could be made over an RPC request.
Javascript kind of wanted to be the more lightweight version of Java in terms of write once run everywhere. Even though is not Java but yet a nother scripting language which was actually an invention of genious which you can comprehent from the JSON notation, which makes it possible to exchange functional data in a simple way.
Java was not so much embraced by the community which just wanted to fast deliver their web apps, PHP just fit the bill.
The cutting edge today respectively the most interesting programming language, if it comes to cloud computing is for sure Dart. Which can run on server and client side, like Java. With all tools necessary for distributed systems, its the definite goto for ubiquitous computing.
With Flutter as a powerful framework to crosscompile for different OS systems, using dart opens a world for shorter development life cycles, similar like Javascript. Therefore in the meanwhile after 10 years of Development, it will be dominant in near future with the new Fuchsia OS.