Here is help for Windows users:
You need to add dictionaries to your computer for Enchant.
1. Enchant looks in your registry keys, I don't know what keys it wants, but it looks here - I ignored all of these:
* Default User\Software\Enchant\Config
* Default User\Software\Enchant\Ispell
* Default User\Software\Enchant\Myspell
2. It looks for OpenOffice dictionaries (from the registry settings for OpenOffice)
3. It looks in folder [PHP]\share\myspell\dicts
I got it working by copying the en-us dictionary files from Firefox into \share\myspell\dicts, and renaming them en_US.*. You can download and install dictionaries from OpenOffice from here I think: http://extensions.services.openoffice.org/dictionary
Enchant creates and writes to the following folder, so you must allow PHP read and write permissions to: [SYSTEM32]\config\systemprofile\Application Data\enchant
It would be convenient if Enchant could accept parameters to specify the location of the main dictionaries and user-dictionaries, I suppose the registry keys are the only way to do it.