This is the IRremote library for the Arduino.

To download from github (http://github.com/shirriff/Arduino-IRremote), click on the "Downloads" link in the upper right, click "Download as zip", and get a zip file.  Unzip it and rename the directory shirriff-Arduino-IRremote-nnn to IRremote

To install, move the downloaded IRremote directory to:
arduino-1.x/libraries/IRremote
where arduino-1.x is your Arduino installation directory

After installation you should have files such as:
arduino-1.x/libraries/IRremote/IRremote.cpp

For details on the library see the Wiki on github or the blog post http://arcfn.com/2009/08/multi-protocol-infrared-remote-library.html

Copyright 2009-2012 Ken Shirriff