• aspell
• ckeditor
• grails

Here's an info dump of some things I did to get Linux aspell-based spell checking working with the Grails CKEditor plugin.

File grails-app/conf/Config.groovy

ckeditor {
    config = "/js/ckeditor/ckconfig.gsp" // CKEDITOR.config.customConfig ; note the gsp extension
    }

File web-app/js/ckeditor/ckconfig.gsp

<%@ page contentType="text/javascript" %>
// http://grails.1312388.n4.nabble.com/ckeditor-custom-plugins-tp2717404p2718562.html
//CKEDITOR.plugins.addExternal('aspell', '${request.contextPath}/js/ckeditor/plugins/aspell/');
CKEDITOR.plugins.addExternal('aspell', '${resource(dir:"js/ckeditor/plugins/aspell/")}');
CKEDITOR.editorConfig = function( config )
{
    config.removePlugins = 'filebrowser,ofm,flash,save,font';
    config.extraPlugins = 'aspell';
    config.toolbar_zinc =
            [
                { name: 'document', items : [ 'Bold', 'Italic', 'NumberedList', 'BulletedList', 'Blockquote', 'Subscript', 'Superscript', 'SpecialChar', '-', 'RemoveFormat' ] },
                { name: 'tools', items : [ 'Source', 'ShowBlocks', '-', 'About', 'Maximize' ] },
                '/',
                { name: 'clipboard', items : [ 'Cut', 'Copy', 'Paste', 'PasteText', 'PasteFromWord', '-', 'Undo', 'Redo' ] },
                { name: 'editing', items : [ 'Find', 'Replace', '-', 'SelectAll', '-', 'SpellCheck' ] },
            ]
};

Get aspell.7z, system pacakges aspell and aspell-en (or your language), and CKEditor plugin aspell. Add the following:

File web-app/js/ckeditor/plugins/aspell/dialogs/aspell.js

oSpeller.spellCheckScript = editor.plugins.aspell.path+'spellerpages/server-scripts/spellchecker.jsp';

File web-app/js/ckeditor/plugins/aspell/spellerpages/server-scripts/spellchecker.jsp is documented in another post about spellchecker