Also wonder if @ryanstout has considered something like that for Volt. The potential speed benefits there could pull a huge amount of people away from Rails…
It depends on what you mean by ‘hot’. Do you mean ‘interesting’ or ‘promising’, or do you mean ‘in actual demand’. I’ll answer both cases anyway.
In terms of right now, i.e. in actual demand, this is what’s hot:
JavaScript frameworks, particularly Angular and React
MapReduce technologies like Hadoop and -even hotter- Apache Spark and their related eco-systems. Not so much the number of jobs but the ridiculous rates such consultants can pull.
DevOps techs like Puppet + Chef
Virtualization techs, like Docker
HTML5 + CSS3 / LESS / SASS
In terms of developing tech, i.e. something that seems set to take off
Functional languages like Clojure, Erlang, Elixir
WebSockets
Ruby on the browser (Opal + Volt)
The Google Stack: Golang + (Python|Node|somelse) + Dart
I’d have to say the Z-machine is the hottest tech.
Scientists have produced superheated gas exceeding temperatures of 2 billion degrees Kelvin, or 3.6 billion degrees Fahrenheit.
This is hotter than the interior of our Sun, which is about 15 million
degrees Kelvin, and also hotter than any previous temperature ever
achieved on Earth, they say.
The Z machine is the largest X-ray generator in the world. It’s
designed to test materials under extreme temperatures and pressures. It
works by releasing 20 million amps of electricity into a vertical array
of very fine tungsten wires. The wires dissolve into a cloud of charged
particles, a superheated gas called plasma.
A very strong magnetic field compresses the plasma into the thickness
of a pencil lead. This causes the plasma to release energy in the form
of X-rays, but the X-rays are usually only several million degrees.