You have two options. You can either use the existing tools file functionality in RadEditor, or use the ASP.NET theming mechanism .
The RadEditor "Prometheus" control maintains backwards compatibility with the old RadEditor for ASP.NET so you can use virtually the same ToolsFile.xml in the new editor as well. The problem with this approach is that you must define all the editor tools in the tools file as well and also the people who change the snippets will also be able to change the editor tools. If you decide to use this approach, then in the code you simply need to set the ToolsFile editor property (a sample tools file is attached to this message):
RadEditor1.ToolsFile = "~/Tools.xml";
The second way to do this takes advantage of ASP.NET themes. Create a theme and add a skin file for the RadEditor control. In this skin file you can configure all RadEditor properties, including snippets. To enable these settings, simply set the page theme in your application. I have attached a sample RadEditor.skin file to this message. If you want to have different snippets for different pages, you can place multiple RadEditor definitions in the skin file and use different SkinID properties.
the Telerik team