1. © 2010 Shivercube
“Do you hear that, Mr. Anderson?That is the
sound of inevitability.” - Agent Smith

2. © 2010 Shivercube
“HelloWorld”.
or
-module(hello).
-export([start/0]).
start() -> io:format(“HelloWorld~n”).

3. © 2010 Shivercube
 Makes hard things easy
 But also makes easy things hard
 Virtual machine called BEAM
 Brutally efficient, and brutally ugly
 Based on Prolog

4. © 2010 Shivercube
 Cloud-based databases
 CouchDB
 SimpleDB
 Facebook Chat
 GitHub egitd
 Yaws
 Wings 3D

5. © 2010 Shivercube
 Functional programming language
 Dynamic typing
 Built for concurrency
 Extremely reliable
 No threading
 Lightweight processes
 “Let it crash” mantra
 Hot-swappable code

6. © 2010 Shivercube
 Programs built entirely out of functions
 No objects anywhere
 Functions are first-class citizens
 Functions usually return the same values,
given the same inputs
 Functions usually do not have side effects
 They usually not modify program state
 Variables can only be assigned to once

7. © 2010 Shivercube
-module(hellov2).
-export([start/0]).
start() ->
spawn(fun() -> loop() end).
loop() ->
receive
hello ->
io:format(“Hello World~n”), loop();
goodbye ->
ok
end.

8. © 2010 Shivercube
 Reality hurts
 Concurrency is hard
 We’ve been using the wrong programming model
▪ Functions and methods with side effects
▪ Threads with shared state

9. © 2010 Shivercube
 Share-nothing processes
 Side effect free
 Concurrency primitives
 Sending messages (!)
 Spawning messages (spawn)
 Receiving messages (receive)

10. © 2010 Shivercube
 Makes hard things easy and easy things hard
 Prolog-style syntax alien to most
 Functional programming paradigm
 Extremely efficient
 Extremely reliable
 “Let it crash” philosophy simplifies code
 Dynamic typing results in better productivity
 Simple concurrency
 Hot swapping code

11. © 2010 Shivercube
 Erlang Programming http://www.erlang.org/
 Erlang (programming language)
http://en.wikipedia.org/wiki/Erlang_(program
ming_language)
 The *Real* Erlang "Hello,World!“
http://egarson.blogspot.com/2008/03/real-
erlang-hello-world.html
 Erlang for C, C++ and Java Programmers
http://tamale.net/erlang/tutorial.shtml