This plugin is aimed only at Firefox users.
In combination with the WriteArea extension it allows to show the Firefox spellchecker suggestions in the CKEditor context menu instead of relying on the SCAYT plugin.
Further explanations at the post in my blog.
License
Licensed under the terms of any of the following licenses at your choice: GPL, LGPL and MPL.
Download
GeckoSpellchecker version 1.0:
download link
Installation
1. Extract the contents of the file into the "plugins" folder of CKEditor.
2. In the CKEditor configuration file (config.js) add the following code:
config.extraPlugins = 'geckospellchecker';