If its use by high-profile startups is any indication, then Scala is on the rise. Running on servers at Foursquare and Twitter, this functional language brings type-safety to the JVM, meaning it can run wherever the JVM works, including Android phones.
Scala is bound to attract more attention as people begin to unpack the lessons from Node.js. Much of the speed and success of Node.js are due to the way it brings a functional programming approach to a stripped-down processor.
That said, the book market suggests that Scala could remain a niche market. Only time will tell whether the general developer populace will follow their startups' Scala lead, but the language shows growth potential among the more experiment-minded set.
Hot scripting language: R
One of the more obscure languages to attract attention lately is R, a tool for compiling statistics. This shouldn't be surprising, given the increasing attention being paid to the terabytes of data sitting around on servers just waiting for someone to try to make some sense of the bits.
The language is a nice collection of classic scripting features borrowed from Lisp and mathematics, married to a large set of routines for statistical analysis. You suck the data into big matrices, then push the button; out comes linear fits, graphs, and other analyses.
The biggest news lately has been two parallel efforts to compile R instead of interpreting it. One, Rcpp, converts R into C++ and pushes the resulting code through a C++ compiler. The other compiles R into bytecode inside the interpreter. Both dramatically speed up the results.
My favorite detail is the way that some clever scientists have hacked R's routines into LaTeX so that you can start with raw data and build the final document. Some call it "reproducible research."
Hot scripting language: PHP
Judging by book sales, you would think that PHP's heyday was done, as PHP book sales dropped 25% from 2009 to 2010.
But a collapse in interest in learning the finer points of PHP is not the same thing as a collapse in PHP use. If anything, it seems to suggest that the platform is quite stable and there's no need to crack the books to learn something new.
The major Web platforms continue to be written in PHP, and if anything, their domination is growing. WordPress, Joomla, and Drupal still attract new developers, and they're all written in PHP. Django, an excellent Python-based framework, continues to lose ground against them in terms of Google Trends search frequency, with WordPress receiving seven times as many searches as Django (minus "jazz," of course, to reduce the effect of the framework's namesake, Django Reinhardt, on trending search results).
A quick scan of the PHP change logs reinforces this stability. There's a nice, reassuring stream of lines that begin "Fixed Bug" and just a few that begin with "Implemented Feature Request." What new features there are seem less aimed at developers and more at helping the server maintenance team with better dashboards and performance.
Newbie scripting language: Java
Scripting purists will look at Java, point to the existence of javac, and say it doesn't belong in the same pile as the simple-to-debug languages mentioned above. Perhaps that's true, but the Java ecosystem is changing, as more and more Java programmers have taken one look at the cool ideas from the scripting world and copied them.
Grabbing ideas, of course, is fair, and the Java world often improves them. Grails, for instance, offers much of the flexibility of a scripting language with the foundation of the JVM. Java Server Pages are so old that people forget them, but the standard server containers for Java all have the compiler built in.
I'm waiting, though, for the Java community to jump on the Node.js bandwagon and write their own unthreaded container that sits on the port and directs the messages to the right object. In the right hands, the performance could be amazing.
This story, "From PHP to Perl: What's hot, what's not in scripting languages" was originally published by InfoWorld.