diff --git a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-debug.js b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-debug.js
index 00abb9c9ce2..9e412cd2727 100644
--- a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-debug.js
+++ b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-debug.js
@@ -34,15 +34,18 @@ YUI.add('moodle-atto_equation-button', function (Y, NAME) {
  */
 
 var COMPONENTNAME = 'atto_equation',
+    LOGNAME = 'atto_equation',
     CSS = {
         EQUATION_TEXT: 'atto_equation_equation',
         EQUATION_PREVIEW: 'atto_equation_preview',
         SUBMIT: 'atto_equation_submit',
         LIBRARY: 'atto_equation_library',
-        LIBRARY_GROUP_PREFIX: 'atto_equation_library'
+        LIBRARY_GROUPS: 'atto_equation_groups',
+        LIBRARY_GROUP_PREFIX: 'atto_equation_group'
     },
     SELECTORS = {
-        LIBRARY_GROUP_PREFIX: '.' + CSS.LIBRARY_GROUP_PREFIX,
+        LIBRARY: '.' + CSS.LIBRARY,
+        LIBRARY_GROUP: '.' + CSS.LIBRARY_GROUPS + ' > div > div',
         EQUATION_TEXT: '.' + CSS.EQUATION_TEXT,
         EQUATION_PREVIEW: '.' + CSS.EQUATION_PREVIEW,
         SUBMIT: '.' + CSS.SUBMIT,
@@ -65,15 +68,19 @@ var COMPONENTNAME = 'atto_equation',
             '<div class="{{CSS.LIBRARY}}">' +
                 '<ul>' +
                     '{{#each library}}' +
-                        '<li><a href="#{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">{{get_string groupname ../component}}</a></li>' +
+                        '<li><a href="#{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '{{get_string groupname ../component}}' +
+                        '</a></li>' +
                     '{{/each}}' +
                 '</ul>' +
-                '<div>' +
+                '<div class="{{CSS.LIBRARY_GROUPS}}">' +
                     '{{#each library}}' +
-                        '<div id="{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">' +
-                        '{{#split "\n" elements}}' +
-                            '<button data-tex="{{this}}" title="{{this}}">$${{this}}$$</button>' +
-                        '{{/split}}' +
+                        '<div id="{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '<div role="toolbar">' +
+                            '{{#split "\n" elements}}' +
+                                '<button tabindex="-1" data-tex="{{this}}" aria-label="{{this}}" title="{{this}}">$${{this}}$$</button>' +
+                            '{{/split}}' +
+                            '</div>' +
                         '</div>' +
                     '{{/each}}' +
                 '</div>' +
@@ -111,7 +118,19 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
      */
     _content: null,
 
+    /**
+     * A reference to the tab focus set on each group.
+     *
+     * The keys are the IDs of the group, the value is the Node on which the focus is set.
+     *
+     * @property _groupFocus
+     * @type Object
+     * @private
+     */
+    _groupFocus: null,
+
     initializer: function() {
+        this._groupFocus = {};
         if (this.get('texfilteractive')) {
             // Add the button to the toolbar.
             this.addButton({
@@ -152,7 +171,7 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         var content = this._getDialogueContent();
         dialogue.set('bodyContent', content);
 
-        var library = content.one(SELECTORS.LIBRARY_GROUP_PREFIX);
+        var library = content.one(SELECTORS.LIBRARY);
 
         var tabview = new Y.TabView({
             srcNode: library
@@ -321,6 +340,17 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
             CSS: CSS
         }));
 
+        // Sets the default focus.
+        this._content.all(SELECTORS.LIBRARY_GROUP).each(function(group) {
+            // The first button gets the focus.
+            this._setGroupTabFocus(group, group.one('button'));
+            // Sometimes the filter adds an anchor in the button, no tabindex on that.
+            group.all('button a').setAttribute('tabindex', '-1');
+        }, this);
+
+        // Keyboard navigation in groups.
+        this._content.delegate('key', this._groupNavigation, 'down:37,39', SELECTORS.LIBRARY_BUTTON, this);
+
         this._content.one(SELECTORS.SUBMIT).on('click', this._setEquation, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('valuechange', this._updatePreview, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('mouseup', this._updatePreview, this);
@@ -330,6 +360,61 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         return this._content;
     },
 
+    /**
+     * Callback handling the keyboard navigation in the groups of the library.
+     *
+     * @param {EventFacade} e The event.
+     * @method _groupNavigation
+     * @private
+     */
+    _groupNavigation: function(e) {
+        e.preventDefault();
+
+        var current = e.currentTarget,
+            parent = current.get('parentNode'), // This must be the <div> containing all the buttons of the group.
+            buttons = parent.all('button'),
+            direction = e.keyCode !== 37 ? 1 : -1,
+            index = buttons.indexOf(current),
+            nextButton;
+
+        if (index < 0) {
+            Y.log('Unable to find the current button in the list of buttons', 'debug', LOGNAME);
+            index = 0;
+        }
+
+        index += direction;
+        if (index < 0) {
+            index = buttons.size() - 1;
+        } else if (index >= buttons.size()) {
+            index = 0;
+        }
+        nextButton = buttons.item(index);
+
+        this._setGroupTabFocus(parent, nextButton);
+        nextButton.focus();
+    },
+
+    /**
+     * Sets tab focus for the group.
+     *
+     * @method _setGroupTabFocus
+     * @param {Node} button The node that focus should now be set to.
+     * @private
+     */
+    _setGroupTabFocus: function(parent, button) {
+        var parentId = parent.generateID();
+
+        // Unset the previous entry.
+        if (typeof this._groupFocus[parentId] !== 'undefined') {
+            this._groupFocus[parentId].setAttribute('tabindex', '-1');
+        }
+
+        // Set on the new entry.
+        this._groupFocus[parentId] = button;
+        button.setAttribute('tabindex', 0);
+        parent.setAttribute('aria-activedescendant', button.generateID());
+    },
+
     /**
      * Reponse to button presses in the TeX library panels.
      *
@@ -343,6 +428,9 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
 
         e.preventDefault();
 
+        // Set the group focus on the button.
+        this._setGroupTabFocus(e.currentTarget.get('parentNode'), e.currentTarget);
+
         input = e.currentTarget.ancestor('.atto_form').one('textarea');
 
         value = input.get('value');
diff --git a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-min.js b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-min.js
index c043250ead3..a15a84eb374 100644
--- a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-min.js
+++ b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button-min.js
@@ -1 +1,2 @@
-YUI.add("moodle-atto_equation-button",function(e,t){var n="atto_equation",r={EQUATION_TEXT:"atto_equation_equation",EQUATION_PREVIEW:"atto_equation_preview",SUBMIT:"atto_equation_submit",LIBRARY:"atto_equation_library",LIBRARY_GROUP_PREFIX:"atto_equation_library"},i={LIBRARY_GROUP_PREFIX:"."+r.LIBRARY_GROUP_PREFIX,EQUATION_TEXT:"."+r.EQUATION_TEXT,EQUATION_PREVIEW:"."+r.EQUATION_PREVIEW,SUBMIT:"."+r.SUBMIT,LIBRARY_BUTTON:"."+r.LIBRARY+" button"},s={FORM:'<form class="atto_form">{{{library}}}<label for="{{elementid}}_{{CSS.EQUATION_TEXT}}">{{{get_string "editequation" component texdocsurl}}}</label><textarea class="fullwidth {{CSS.EQUATION_TEXT}}" id="{{elementid}}_{{CSS.EQUATION_TEXT}}" rows="8"></textarea><br/><label for="{{elementid}}_{{CSS.EQUATION_PREVIEW}}">{{get_string "preview" component}}</label><div class="fullwidth {{CSS.EQUATION_PREVIEW}}" id="{{elementid}}_{{CSS.EQUATION_PREVIEW}}"></div><div class="mdl-align"><br/><button class="{{CSS.SUBMIT}}">{{get_string "saveequation" component}}</button></div></form>',LIBRARY:'<div class="{{CSS.LIBRARY}}"><ul>{{#each library}}<li><a href="#{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">{{get_string groupname ../component}}</a></li>{{/each}}</ul><div>{{#each library}}<div id="{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">{{#split "\n" elements}}<button data-tex="{{this}}" title="{{this}}">$${{this}}$$</button>{{/split}}</div>{{/each}}</div></div>'};e.namespace("M.atto_equation").Button=e.Base.create("button",e.M.editor_atto.EditorPlugin,[],{_currentSelection:null,_lastCursorPos:0,_content:null,initializer:function(){this.get("texfilteractive")&&(this.addButton({icon:"e/math",callback:this._displayDialogue}),this.get("host").on("atto:selectionchanged",function(){this._resolveEquation()?this.highlightButtons():this.unHighlightButtons()},this))},_displayDialogue:function(){this._currentSelection=this.get("host").getSelection();if(this._currentSelection===!1)return;var t=this.getDialogue({headerContent:M.util.get_string("pluginname",n),focusAfterHide:!0,width:600}),r=this._getDialogueContent();t.set("bodyContent",r);var s=r.one(i.LIBRARY_GROUP_PREFIX),o=new e.TabView({srcNode:s});o.render(),t.show();var u=this._resolveEquation();u&&r.one(i.EQUATION_TEXT).set("text",u),this._updatePreview(!1)},_resolveEquation:function(){var t=this.get("host").getSelectionParentNode(),n,r;return t?(n=e.one(t).get("text"),pattern=/\$\$[\S\s]*\$\$/,r=pattern.exec(n),r&&r.length?(r=r.pop(),r=r.substring(2,r.length-2),r):!1):!1},_setEquation:function(t){var n,r,i,s,o,u,a=this.get("host");t.preventDefault(),this.getDialogue({focusAfterHide:null}).hide(),n=t.currentTarget.ancestor(".atto_form").one("textarea"),u=n.get("value"),u!==""&&(a.setSelection(this._currentSelection),u="$$ "+u.trim()+" $$",r=e.one(a.getSelectionParentNode()),i=r.get("text"),s=/\$\$[\S\s]*\$\$/,o=s.exec(i),o&&o.length?(o=o.pop(),i=i.replace(o,"$$"+u+"$$"),r.set("text",i)):a.insertContentAtFocusPoint(u),this.markUpdated())},_updatePreview:function(t){var n=this._content.one(i.EQUATION_TEXT),r=n.get("value"),s,o,u=n.get("selectionStart"),a="",f="\\square ",l;t&&t.preventDefault(),u||(u=0);while(r.charAt(u)==="\\"&&u>0)u-=1;l=/[\w\{\}]/;while(l.test(r.charAt(u))&&u<r.length)u+=1;this._lastCursorPos=u,r=a+r.substring(0,u)+f+r.substring(u),s=M.cfg.wwwroot+"/lib/editor/atto/plugins/equation/ajax.php",params={sesskey:M.cfg.sesskey,contextid:this.get("contextid"),action:"filtertext",text:"$$ "+r+" $$"},o=e.io(s,{sync:!0,data:params}),o.status===200&&this._content.one(i.EQUATION_PREVIEW).setHTML(o.responseText)},_getDialogueContent:function(){var t=this._getLibraryContent(),o=e.Handlebars.compile(s.FORM);return this._content=e.Node.create(o({elementid:this.get("host").get("elementid"),component:n,library:t,texdocsurl:this.get("texdocsurl"),CSS:r})),this._content.one(i.SUBMIT).on("click",this._setEquation,this),this._content.one(i.EQUATION_TEXT).on("valuechange",this._updatePreview,this),this._content.one(i.EQUATION_TEXT).on("mouseup",this._updatePreview,this),this._content.one(i.EQUATION_TEXT).on("keyup",this._updatePreview,this),this._content.delegate("click",this._selectLibraryItem,i.LIBRARY_BUTTON,this),this._content},_selectLibraryItem:function(e){var t=e.currentTarget.getAttribute("data-tex");e.preventDefault(),input=e.currentTarget.ancestor(".atto_form").one("textarea"),value=input.get("value"),value=value.substring(0,this._lastCursorPos)+t+value.substring(this._lastCursorPos,value.length),input.set("value",value),input.focus();var n=this._lastCursorPos+t.length,r=input.getDOMNode();if(typeof r.selectionStart=="number")r.selectionStart=r.selectionEnd=n;else if(typeof r.createTextRange!="undefined"){var i=r.createTextRange();i.moveToPoint(n),i.select()}this._updatePreview(!1)},_getLibraryContent:function(){var t=e.Handlebars.compile(s.LIBRARY),i=this.get("library"),o="";e.Handlebars.registerHelper("split",function(e,t,n){var r,i,s;if(typeof e=="undefined"||typeof t=="undefined")return"";s="",r=t.trim().split(e);while(r.length>0)i=r.shift(),s+=n.fn(i);return s}),o=t({elementid:this.get("host").get("elementid"),component:n,library:i,CSS:r});var u=M.cfg.wwwroot+"/lib/editor/atto/plugins/equation/ajax.php",a={sesskey:M.cfg.sesskey,contextid:this.get("contextid"),action:"filtertext",text:o};return preview=e.io(u,{sync:!0,data:a,method:"POST"}),preview.status===200&&(o=preview.responseText),o}},{ATTRS:{texfilteractive:{value:!1},contextid:{value:null},library:{value:{}},texdocsurl:{value:null}}})},"@VERSION@",{requires:["moodle-editor_atto-plugin","io","event-valuechange","tabview"]});
+YUI.add("moodle-atto_equation-button",function(e,t){var n="atto_equation",r="atto_equation",i={EQUATION_TEXT:"atto_equation_equation",EQUATION_PREVIEW:"atto_equation_preview",SUBMIT:"atto_equation_submit",LIBRARY:"atto_equation_library",LIBRARY_GROUPS:"atto_equation_groups",LIBRARY_GROUP_PREFIX:"atto_equation_group"},s={LIBRARY:"."+i.LIBRARY,LIBRARY_GROUP:"."+i.LIBRARY_GROUPS+" > div > div",EQUATION_TEXT:"."+i.EQUATION_TEXT,EQUATION_PREVIEW:"."+i.EQUATION_PREVIEW,SUBMIT:"."+i.SUBMIT,LIBRARY_BUTTON:"."+i.LIBRARY+" button"},o={FORM:'<form class="atto_form">{{{library}}}<label for="{{elementid}}_{{CSS.EQUATION_TEXT}}">{{{get_string "editequation" component texdocsurl}}}</label><textarea class="fullwidth {{CSS.EQUATION_TEXT}}" id="{{elementid}}_{{CSS.EQUATION_TEXT}}" rows="8"></textarea><br/><label for="{{elementid}}_{{CSS.EQUATION_PREVIEW}}">{{get_string "preview" component}}</label><div class="fullwidth {{CSS.EQUATION_PREVIEW}}" id="{{elementid}}_{{CSS.EQUATION_PREVIEW}}"></div><div class="mdl-align"><br/><button class="{{CSS.SUBMIT}}">{{get_string "saveequation" component}}</button></div></form>',LIBRARY:'<div class="{{CSS.LIBRARY}}"><ul>{{#each library}}<li><a href="#{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">{{get_string groupname ../component}}</a></li>{{/each}}</ul><div class="{{CSS.LIBRARY_GROUPS}}">{{#each library}}<div id="{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}"><div role="toolbar">{{#split "\n" elements}}<button tabindex="-1" data-tex="{{this}}" aria-label="{{this}}" title="{{this}}">$${{this}}$$</button>{{/split}}</div></div>{{/each}}</div></div>'};e.namespace("M.atto_equation").Button=e.Base.create("button",e.M.editor_atto.EditorPlugin,[],{_currentSelection:null,_lastCursorPos:0,_content:null,_groupFocus:null,initializer:function(){this._groupFocus={},this.get("texfilteractive")&&(this.addButton({icon:"e/math",callback:this._displayDialogue}),this.get("host").on("atto:selectionchanged",function(){this._resolveEquation()?this.highlightButtons():this.unHighlightButtons()},this))},_displayDialogue:function(){this._currentSelection=this.get("host").getSelection();if(this._currentSelection===!1)return;var t=this.getDialogue({headerContent:M.util.get_string("pluginname",n),focusAfterHide:!0,width:600}),r=this._getDialogueContent();t.set("bodyContent",r);var i=r.one(s.LIBRARY),o=new e.TabView({srcNode:i});o.render(),t.show();var u=this._resolveEquation();u&&r.one(s.EQUATION_TEXT).set("text",u),this._updatePreview(!1)},_resolveEquation:function(){var t=this.get("host").getSelectionParentNode(),n,r;return t?(n=e.one(t).get("text"),pattern=/\$\$[\S\s]*\$\$/,r=pattern.exec(n),r&&r.length?(r=r.pop(),r=r.substring(2,r.length-2),r):!1):!1},_setEquation:function(t){var n,r,i,s,o,u,a=this.get("host");t.preventDefault(),this.getDialogue({focusAfterHide:null}).hide(),n=t.currentTarget.ancestor(".atto_form").one("textarea"),u=n.get("value"),u!==""&&(a.setSelection(this._currentSelection),u="$$ "+u.trim()+" $$",r=e.one(a.getSelectionParentNode()),i=r.get("text"),s=/\$\$[\S\s]*\$\$/,o=s.exec(i),o&&o.length?(o=o.pop(),i=i.replace(o,"$$"+u+"$$"),r.set("text",i)):a.insertContentAtFocusPoint(u),this.markUpdated())},_updatePreview:function(t){var n=this._content.one(s.EQUATION_TEXT),r=n.get("value"),i,o,u=n.get("selectionStart"),a="",f="\\square ",l;t&&t.preventDefault(),u||(u=0);while(r.charAt(u)==="\\"&&u>0)u-=1;l=/[\w\{\}]/;while(l.test(r.charAt(u))&&u<r.length)u+=1;this._lastCursorPos=u,r=a+r.substring(0,u)+f+r.substring(u),i=M.cfg.wwwroot+"/lib/editor/atto/plugins/equation/ajax.php",params={sesskey:M.cfg.sesskey,contextid:this.get("contextid"),action:"filtertext",text:"$$ "+r+" $$"},o=e.io(i,{sync:!0,data:params}),o.status===200&&this._content.one(s.EQUATION_PREVIEW).setHTML(o.responseText)},_getDialogueContent:function(){var t=this._getLibraryContent(),r=e.Handlebars.compile(o.FORM);return this._content=e.Node.create(r({elementid:this.get("host").get("elementid"),component:n,library:t,texdocsurl:this.get("texdocsurl"),CSS:i})),this._content.all(s.LIBRARY_GROUP).each(function(e){this._setGroupTabFocus(e,e.one("button")),e.all("button a").setAttribute("tabindex","-1")},this),this._content.delegate("key",this._groupNavigation,"down:37,39",s.LIBRARY_BUTTON,this),this._content.one(s.SUBMIT).on("click",this._setEquation,this),this._content.one(s.EQUATION_TEXT).on("valuechange",this._updatePreview,this),this._content.one(s.EQUATION_TEXT).on("mouseup",this._updatePreview,this),this._content.one(s.EQUATION_TEXT).on("keyup",this._updatePreview,this),this._content.delegate("click",this._selectLibraryItem,s.LIBRARY_BUTTON,this),this._content},_groupNavigation:function(e){e.preventDefault();var t=e.currentTarget,n=t.get("parentNode"),r=n.all("button"),i=e.keyCode!==37?1:-1,s=r.indexOf(t),o;s<0&&(s=0),s+=i,s<0?s=r.size()-1:s>=r.size()&&(s=0),o=r.item(s),this._setGroupTabFocus(n,o),o.focus()},_setGroupTabFocus:function(e,t){var n=e.generateID();typeof this._groupFocus[n]!="undefined"&&this._groupFocus[n].setAttribute("tabindex","-1"),this._groupFocus[n]=t,t.setAttribute("tabindex",0),e.setAttribute("aria-activedescendant",t.generateID())},_selectLibraryItem:function(e){var t=e.currentTarget.getAttribute("data-tex");e.preventDefault(),this._setGroupTabFocus(e.currentTarget.get("parentNode"),e.currentTarget),input=e.currentTarget.ancestor(".atto_form").one("textarea"),value=input.get("value"),value=value.substring(0,this._lastCursorPos)+t+value.substring(this._lastCursorPos,value.length),input.set("value",value),input.focus();var n=this._lastCursorPos+t.length,r=input.getDOMNode();if(typeof r.selectionStart=="number")r.selectionStart=r.selectionEnd=n;else if(typeof r.createTextRange!="undefined"){var i=r.createTextRange();i.moveToPoint(n),i.select()}this._updatePreview(!1)},_getLibraryContent:function(){var t=e.Handlebars.compile(o.LIBRARY),r=this.get("library"),s="";e.Handlebars.registerHelper("split",function(e,t,n){var r,i,s;if(typeof e=="undefined"||typeof t=="undefined")return""
+;s="",r=t.trim().split(e);while(r.length>0)i=r.shift(),s+=n.fn(i);return s}),s=t({elementid:this.get("host").get("elementid"),component:n,library:r,CSS:i});var u=M.cfg.wwwroot+"/lib/editor/atto/plugins/equation/ajax.php",a={sesskey:M.cfg.sesskey,contextid:this.get("contextid"),action:"filtertext",text:s};return preview=e.io(u,{sync:!0,data:a,method:"POST"}),preview.status===200&&(s=preview.responseText),s}},{ATTRS:{texfilteractive:{value:!1},contextid:{value:null},library:{value:{}},texdocsurl:{value:null}}})},"@VERSION@",{requires:["moodle-editor_atto-plugin","io","event-valuechange","tabview"]});
diff --git a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button.js b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button.js
index 76df89c2ec8..19a1daeaa49 100644
--- a/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button.js
+++ b/lib/editor/atto/plugins/equation/yui/build/moodle-atto_equation-button/moodle-atto_equation-button.js
@@ -34,15 +34,18 @@ YUI.add('moodle-atto_equation-button', function (Y, NAME) {
  */
 
 var COMPONENTNAME = 'atto_equation',
+    LOGNAME = 'atto_equation',
     CSS = {
         EQUATION_TEXT: 'atto_equation_equation',
         EQUATION_PREVIEW: 'atto_equation_preview',
         SUBMIT: 'atto_equation_submit',
         LIBRARY: 'atto_equation_library',
-        LIBRARY_GROUP_PREFIX: 'atto_equation_library'
+        LIBRARY_GROUPS: 'atto_equation_groups',
+        LIBRARY_GROUP_PREFIX: 'atto_equation_group'
     },
     SELECTORS = {
-        LIBRARY_GROUP_PREFIX: '.' + CSS.LIBRARY_GROUP_PREFIX,
+        LIBRARY: '.' + CSS.LIBRARY,
+        LIBRARY_GROUP: '.' + CSS.LIBRARY_GROUPS + ' > div > div',
         EQUATION_TEXT: '.' + CSS.EQUATION_TEXT,
         EQUATION_PREVIEW: '.' + CSS.EQUATION_PREVIEW,
         SUBMIT: '.' + CSS.SUBMIT,
@@ -65,15 +68,19 @@ var COMPONENTNAME = 'atto_equation',
             '<div class="{{CSS.LIBRARY}}">' +
                 '<ul>' +
                     '{{#each library}}' +
-                        '<li><a href="#{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">{{get_string groupname ../component}}</a></li>' +
+                        '<li><a href="#{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '{{get_string groupname ../component}}' +
+                        '</a></li>' +
                     '{{/each}}' +
                 '</ul>' +
-                '<div>' +
+                '<div class="{{CSS.LIBRARY_GROUPS}}">' +
                     '{{#each library}}' +
-                        '<div id="{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">' +
-                        '{{#split "\n" elements}}' +
-                            '<button data-tex="{{this}}" title="{{this}}">$${{this}}$$</button>' +
-                        '{{/split}}' +
+                        '<div id="{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '<div role="toolbar">' +
+                            '{{#split "\n" elements}}' +
+                                '<button tabindex="-1" data-tex="{{this}}" aria-label="{{this}}" title="{{this}}">$${{this}}$$</button>' +
+                            '{{/split}}' +
+                            '</div>' +
                         '</div>' +
                     '{{/each}}' +
                 '</div>' +
@@ -111,7 +118,19 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
      */
     _content: null,
 
+    /**
+     * A reference to the tab focus set on each group.
+     *
+     * The keys are the IDs of the group, the value is the Node on which the focus is set.
+     *
+     * @property _groupFocus
+     * @type Object
+     * @private
+     */
+    _groupFocus: null,
+
     initializer: function() {
+        this._groupFocus = {};
         if (this.get('texfilteractive')) {
             // Add the button to the toolbar.
             this.addButton({
@@ -152,7 +171,7 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         var content = this._getDialogueContent();
         dialogue.set('bodyContent', content);
 
-        var library = content.one(SELECTORS.LIBRARY_GROUP_PREFIX);
+        var library = content.one(SELECTORS.LIBRARY);
 
         var tabview = new Y.TabView({
             srcNode: library
@@ -321,6 +340,17 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
             CSS: CSS
         }));
 
+        // Sets the default focus.
+        this._content.all(SELECTORS.LIBRARY_GROUP).each(function(group) {
+            // The first button gets the focus.
+            this._setGroupTabFocus(group, group.one('button'));
+            // Sometimes the filter adds an anchor in the button, no tabindex on that.
+            group.all('button a').setAttribute('tabindex', '-1');
+        }, this);
+
+        // Keyboard navigation in groups.
+        this._content.delegate('key', this._groupNavigation, 'down:37,39', SELECTORS.LIBRARY_BUTTON, this);
+
         this._content.one(SELECTORS.SUBMIT).on('click', this._setEquation, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('valuechange', this._updatePreview, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('mouseup', this._updatePreview, this);
@@ -330,6 +360,60 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         return this._content;
     },
 
+    /**
+     * Callback handling the keyboard navigation in the groups of the library.
+     *
+     * @param {EventFacade} e The event.
+     * @method _groupNavigation
+     * @private
+     */
+    _groupNavigation: function(e) {
+        e.preventDefault();
+
+        var current = e.currentTarget,
+            parent = current.get('parentNode'), // This must be the <div> containing all the buttons of the group.
+            buttons = parent.all('button'),
+            direction = e.keyCode !== 37 ? 1 : -1,
+            index = buttons.indexOf(current),
+            nextButton;
+
+        if (index < 0) {
+            index = 0;
+        }
+
+        index += direction;
+        if (index < 0) {
+            index = buttons.size() - 1;
+        } else if (index >= buttons.size()) {
+            index = 0;
+        }
+        nextButton = buttons.item(index);
+
+        this._setGroupTabFocus(parent, nextButton);
+        nextButton.focus();
+    },
+
+    /**
+     * Sets tab focus for the group.
+     *
+     * @method _setGroupTabFocus
+     * @param {Node} button The node that focus should now be set to.
+     * @private
+     */
+    _setGroupTabFocus: function(parent, button) {
+        var parentId = parent.generateID();
+
+        // Unset the previous entry.
+        if (typeof this._groupFocus[parentId] !== 'undefined') {
+            this._groupFocus[parentId].setAttribute('tabindex', '-1');
+        }
+
+        // Set on the new entry.
+        this._groupFocus[parentId] = button;
+        button.setAttribute('tabindex', 0);
+        parent.setAttribute('aria-activedescendant', button.generateID());
+    },
+
     /**
      * Reponse to button presses in the TeX library panels.
      *
@@ -343,6 +427,9 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
 
         e.preventDefault();
 
+        // Set the group focus on the button.
+        this._setGroupTabFocus(e.currentTarget.get('parentNode'), e.currentTarget);
+
         input = e.currentTarget.ancestor('.atto_form').one('textarea');
 
         value = input.get('value');
diff --git a/lib/editor/atto/plugins/equation/yui/src/button/js/button.js b/lib/editor/atto/plugins/equation/yui/src/button/js/button.js
index a5af93df7ef..e84acfc54ab 100644
--- a/lib/editor/atto/plugins/equation/yui/src/button/js/button.js
+++ b/lib/editor/atto/plugins/equation/yui/src/button/js/button.js
@@ -32,15 +32,18 @@
  */
 
 var COMPONENTNAME = 'atto_equation',
+    LOGNAME = 'atto_equation',
     CSS = {
         EQUATION_TEXT: 'atto_equation_equation',
         EQUATION_PREVIEW: 'atto_equation_preview',
         SUBMIT: 'atto_equation_submit',
         LIBRARY: 'atto_equation_library',
-        LIBRARY_GROUP_PREFIX: 'atto_equation_library'
+        LIBRARY_GROUPS: 'atto_equation_groups',
+        LIBRARY_GROUP_PREFIX: 'atto_equation_group'
     },
     SELECTORS = {
-        LIBRARY_GROUP_PREFIX: '.' + CSS.LIBRARY_GROUP_PREFIX,
+        LIBRARY: '.' + CSS.LIBRARY,
+        LIBRARY_GROUP: '.' + CSS.LIBRARY_GROUPS + ' > div > div',
         EQUATION_TEXT: '.' + CSS.EQUATION_TEXT,
         EQUATION_PREVIEW: '.' + CSS.EQUATION_PREVIEW,
         SUBMIT: '.' + CSS.SUBMIT,
@@ -63,15 +66,19 @@ var COMPONENTNAME = 'atto_equation',
             '<div class="{{CSS.LIBRARY}}">' +
                 '<ul>' +
                     '{{#each library}}' +
-                        '<li><a href="#{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">{{get_string groupname ../component}}</a></li>' +
+                        '<li><a href="#{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '{{get_string groupname ../component}}' +
+                        '</a></li>' +
                     '{{/each}}' +
                 '</ul>' +
-                '<div>' +
+                '<div class="{{CSS.LIBRARY_GROUPS}}">' +
                     '{{#each library}}' +
-                        '<div id="{{elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}{{@key}}">' +
-                        '{{#split "\n" elements}}' +
-                            '<button data-tex="{{this}}" title="{{this}}">$${{this}}$$</button>' +
-                        '{{/split}}' +
+                        '<div id="{{../elementid}}_{{../CSS.LIBRARY_GROUP_PREFIX}}_{{@key}}">' +
+                            '<div role="toolbar">' +
+                            '{{#split "\n" elements}}' +
+                                '<button tabindex="-1" data-tex="{{this}}" aria-label="{{this}}" title="{{this}}">$${{this}}$$</button>' +
+                            '{{/split}}' +
+                            '</div>' +
                         '</div>' +
                     '{{/each}}' +
                 '</div>' +
@@ -109,7 +116,19 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
      */
     _content: null,
 
+    /**
+     * A reference to the tab focus set on each group.
+     *
+     * The keys are the IDs of the group, the value is the Node on which the focus is set.
+     *
+     * @property _groupFocus
+     * @type Object
+     * @private
+     */
+    _groupFocus: null,
+
     initializer: function() {
+        this._groupFocus = {};
         if (this.get('texfilteractive')) {
             // Add the button to the toolbar.
             this.addButton({
@@ -150,7 +169,7 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         var content = this._getDialogueContent();
         dialogue.set('bodyContent', content);
 
-        var library = content.one(SELECTORS.LIBRARY_GROUP_PREFIX);
+        var library = content.one(SELECTORS.LIBRARY);
 
         var tabview = new Y.TabView({
             srcNode: library
@@ -319,6 +338,17 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
             CSS: CSS
         }));
 
+        // Sets the default focus.
+        this._content.all(SELECTORS.LIBRARY_GROUP).each(function(group) {
+            // The first button gets the focus.
+            this._setGroupTabFocus(group, group.one('button'));
+            // Sometimes the filter adds an anchor in the button, no tabindex on that.
+            group.all('button a').setAttribute('tabindex', '-1');
+        }, this);
+
+        // Keyboard navigation in groups.
+        this._content.delegate('key', this._groupNavigation, 'down:37,39', SELECTORS.LIBRARY_BUTTON, this);
+
         this._content.one(SELECTORS.SUBMIT).on('click', this._setEquation, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('valuechange', this._updatePreview, this);
         this._content.one(SELECTORS.EQUATION_TEXT).on('mouseup', this._updatePreview, this);
@@ -328,6 +358,61 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
         return this._content;
     },
 
+    /**
+     * Callback handling the keyboard navigation in the groups of the library.
+     *
+     * @param {EventFacade} e The event.
+     * @method _groupNavigation
+     * @private
+     */
+    _groupNavigation: function(e) {
+        e.preventDefault();
+
+        var current = e.currentTarget,
+            parent = current.get('parentNode'), // This must be the <div> containing all the buttons of the group.
+            buttons = parent.all('button'),
+            direction = e.keyCode !== 37 ? 1 : -1,
+            index = buttons.indexOf(current),
+            nextButton;
+
+        if (index < 0) {
+            Y.log('Unable to find the current button in the list of buttons', 'debug', LOGNAME);
+            index = 0;
+        }
+
+        index += direction;
+        if (index < 0) {
+            index = buttons.size() - 1;
+        } else if (index >= buttons.size()) {
+            index = 0;
+        }
+        nextButton = buttons.item(index);
+
+        this._setGroupTabFocus(parent, nextButton);
+        nextButton.focus();
+    },
+
+    /**
+     * Sets tab focus for the group.
+     *
+     * @method _setGroupTabFocus
+     * @param {Node} button The node that focus should now be set to.
+     * @private
+     */
+    _setGroupTabFocus: function(parent, button) {
+        var parentId = parent.generateID();
+
+        // Unset the previous entry.
+        if (typeof this._groupFocus[parentId] !== 'undefined') {
+            this._groupFocus[parentId].setAttribute('tabindex', '-1');
+        }
+
+        // Set on the new entry.
+        this._groupFocus[parentId] = button;
+        button.setAttribute('tabindex', 0);
+        parent.setAttribute('aria-activedescendant', button.generateID());
+    },
+
     /**
      * Reponse to button presses in the TeX library panels.
      *
@@ -341,6 +426,9 @@ Y.namespace('M.atto_equation').Button = Y.Base.create('button', Y.M.editor_atto.
 
         e.preventDefault();
 
+        // Set the group focus on the button.
+        this._setGroupTabFocus(e.currentTarget.get('parentNode'), e.currentTarget);
+
         input = e.currentTarget.ancestor('.atto_form').one('textarea');
 
         value = input.get('value');