based applications.
To use Elixir on Ubuntu, install the package elixir.
Erlang
From the official website, “Erlang is a programming language used to build
massively scalable soft real-time systems with requirements on high
availability. Some of its uses are in telecoms, banking, e-commerce, computer
telephony and instant messaging. Erlang’s runtime system has built-in support
for concurrency, distribution and fault tolerance.” (© Erlang) Erlang is a
declarative, functional language that includes real-time garbage collection and
hot-swapping of code. It is primarily designed for distributed applications that
require extreme uptime.
Erlang’s greatest strength is its ability to create a large number of concurrent
processes, each with low overhead, and allow them to communicate with one
another using an asynchronous message handling system. In addition, the
Erlang developers have a philosophy of development that emphasizes keeping
things running, meaning that future stable Erlang updates should not break
running code. They like to test extensively and try to break as much as
possible in testing to prevent breakage in production systems. One of the
technical editors mentioned a neat feature while reading this chapter: Erlang’s
processes can communicate with each other even if they don’t live on the
same box. You have to explicitly allow this in your code, but the ability is
built in to the language runtime and syntax and is not a third-party library.
To use Erlang on Ubuntu, you write programs in your favorite text editor. To
compile, you need the package erlang, which installs the Erlang/OTP
runtime, applications, sources, code examples, and the Erlang editing mode
for emacs.
Forth
Forth, which first appeared in the 1970s, is an interactive, procedural,
imperative language with typeless data that runs as a shell. Sets of instructions
can be saved and compiled as bytecode programs. It is a very small language
by itself and is therefore very useful in boot loaders and embedded systems,
and it has even been used by NASA in space applications.
On the surface, Forth is a simple language, but it is highly extensible. In
essence, a programmer creates a dictionary, beginning with a small set of
predefined words. These are combined in new ways to extend the lexicon and