EcmaScript and the Server Ribbon
Last modified: February 07, 2011
Applies to: SharePoint Foundation 2010
Target a delegate control on the page, such as AdditionalPageHead.
Add a Web Part on the page.
Use ScriptLink for the Location attribute on a custom action.
The type of customization you use depends on the scope of the scenario. For an example of a site collection–level replacement of a button on the ribbon, see Walkthrough: Replacing a Button on the Server Ribbon for a Site Collection.