As described in a help file from Adobe a new option for hyphenation was added to InDesign CS6 (in fact it appeared in version ID 5.5) and continues in InDesign CC. Hunspell is a free software and widely used in various applications you might be using every day. This option makes it possible to add hyphenation for about 90 languages that are not in the standard installation of InDesign, including Icelandic.
The before-mentioned file describes how to install a dictionary for a language you want to add, where to get the dictionary and how to activate the dictionary. Knowing that this kind of installation would make many designers faint and even prevent them from installing and also knowing that I had to install to almost 30 macs, I made an installer for the mac. I then decided to make the installer freely available for anyone who wants Icelandic hyphenation on InDesign. You can download the appropriate installer using the links below.
InDesign CC 2015: Some changes in the InDesign application setup make the previous installers obsolite for CC 2015. I made an installer for the CC 2015 version.
Installer for Hunspell Icelandic hyphenation, Indesign CS6
Installer for Hunspell Icelandic hyphenation, Indesign CC
Installer for Hunspell Icelandic hyphenation, Indesign CC 2014
Installer for Hunspell Icelandic hyphenation, Indesign CC 2015