runescape
The edit toolbar.
The edit toolbar.

With the upgrade to MediaWiki 1.9, users can now easily customise the edit toolbar. To do this, you can either edit the monobook.js or created your own monobook by doing placing [[User:Example/Monobook.js]] on your user page. However, only admins can edit the site-wide monobook, so you'll have to discuss changes with them to have buttons added to the entire wiki.

How to make a new button

The first thing to do is create a 23x22 image (you can use Wikia's blank button as a template) and upload it or use one of Wikia's already made buttons.

After that, you simply edit your user js or site-wide js. Shown below are examples on how to do this. 

 if (mwCustomEditButtons) {
   mwCustomEditButtons[mwCustomEditButtons.length] = {
     "imageFile": "http://images.wikia.com/central/images/c/c8/Button_redirect.png",
     "speedTip": "Redirect",
     "tagOpen": "#REDIRECT [[",
     "tagClose": "]]",
     "sampleText": "Insert text"};
 
   mwCustomEditButtons[mwCustomEditButtons.length] = {
     "imageFile": "http://images.wikia.com/central/images/c/c9/Button_strike.png",
     "speedTip": "Strike",
     "tagOpen": "<s>",
     "tagClose": "</s>",
     "sampleText": "Strike-through text"};
 
   mwCustomEditButtons[mwCustomEditButtons.length] = {
     "imageFile": "http://images.wikia.com/central/images/1/13/Button_enter.png",
     "speedTip": "Line break",
     "tagOpen": "<br />",
     "tagClose": "",
     "sampleText": ""};

   mwCustomEditButtons[mwCustomEditButtons.length] = {
     "imageFile": "http://images.wikia.com/central/images/7/74/Button_comment.png",
     "speedTip": "Comment visible only for editors",
     "tagOpen": "<!-- ",
     "tagClose": " -->",
     "sampleText": "Insert comment here"}
  }