Firefox users can search Gramene using QuickSearch functionality via an OpenSearch plugin. To enable it, click on your default search engine in your search box. This is usually the Google "G".
In the pop up menu, choose "Add Gramene Quicksearch"
You'll note that your search icon changes to the Gramene icon. You can now search Gramene from your search engine field. To switch to a different engine, or to return to searching Gramene at a later point, simply pop up your engine choice menu again and choose "Gramene."
If you wish to delete your Gramene search engine, choose "Manage Search Engines...", select Gramene, and then press "Delete".